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Basic Swift MCQ

1. How can you extract val to x in tuple vt? let vt = (name: "ABC", val: 5)

Let x = vt.1

All of these answers

Let x = vt.val

Let (_, x) = vt

Answer

Correct Answer: All of these answers

Note: This Question is unanswered, help us to find answer for this one

2. What is the type of vals in this code? let vals = ["a", 1, "Hi"]

Array(char)

[Any]

Array

[Generic]

Answer

Correct Answer: [Any]

Note: This Question is unanswered, help us to find answer for this one

3. What is the value of numbers in the code below? let numbers = [1,2,3,4,5,6].filter{ $0 % 2 == 0}

[1,3,5]

[]

[2,4,6]

Nil

Answer

Correct Answer: [2,4,6]

Note: This Question is unanswered, help us to find answer for this one

4. In the code below, AOM must be a(n)? class AmP : MMM, AOM { }

Class

Protocol

Enumeration

Struct

Answer

Correct Answer: Protocol

Note: This Question is unanswered, help us to find answer for this one

5. What enumeration feature allows them to store case-specific data? (Question does not make that much sense though. )

Associated values

Integral values

Raw values

Custom values

Answer

Correct Answer: Associated values

Note: This Question is unanswered, help us to find answer for this one

6. What is printed to the console when this code is executed? "t".forEach { (char) in; print(char) }

Nil

Nothing, since the code contains an error

Zero

Answer

Correct Answer: t

Note: This Question is unanswered, help us to find answer for this one

7. What is the value of val after this code is executed? let i = 5; let val = i * 6.0

This code is invalid.

Answer

Correct Answer: This code is invalid.

Note: This Question is unanswered, help us to find answer for this one

8. What is true of this code? let name: String?

Name can hold only a string value.

Name can hold either a string or nil value.

Optional values cannot be let constants.

Only non-empty string variables can be stored in name

Answer

Correct Answer: Name can hold either a string or nil value.

Note: This Question is unanswered, help us to find answer for this one

9. What does this code print? let names = ["Bear", "Tony", "Svante"] print(names[1]+"Bear")

1Bear

BearBear

TonyBear

Nothing, this code is invalid

Answer

Correct Answer: TonyBear

Note: This Question is unanswered, help us to find answer for this one

10. How many times this code will be executed? —OR— How many times will this loop be performed? for i in ["0", "1"]{print(i)}

One

Two

Three

This code does not compile

Answer

Correct Answer: Two

Note: This Question is unanswered, help us to find answer for this one

11. How do you declare an optional String?

String?

Optional[String]

[String]?

?String

Answer

Correct Answer: String?

Note: This Question is unanswered, help us to find answer for this one

12. When is deinit called?

When a class instance needs memory

All of these answers

When the executable code is finished

When a class instance is being removed from memory

Answer

Correct Answer: All of these answers

Note: This Question is unanswered, help us to find answer for this one

13. DispatchQueue.main.async takes a block that will be

Not executed

Executed in the main queue

None of these answers

Executed on the background thread

Answer

Correct Answer: Executed in the main queue

Note: This Question is unanswered, help us to find answer for this one

14. How can you sort this array?

Var vals = [1,2,3]

Vals.sort { $0 < $1 }

Vals.sort { (s1, s2) in s1 < s2 }

Vals.sort(by: <)

All of these answers

Answer

Correct Answer: All of these answers

Note: This Question is unanswered, help us to find answer for this one

15. What prints to the console when executing this code? let x = try? String.init("test") print(x)

Nil

Nothing - this code contains an error

Optional("test")

Test

Answer

Correct Answer: Optional("test")

Note: This Question is unanswered, help us to find answer for this one

16. What is wrong with this code? Let val = 5.0 + 10

There is nothing wrong with this code

Val is a constant and cannot be changed

5.0 and 10 are different types

There is no semicolon

Answer

Correct Answer: There is nothing wrong with this code

Note: This Question is unanswered, help us to find answer for this one

17. What is wrong with this code? var x = 5; x = 10.0

You cannot assign a Double to a variable of type Int

X is undefined

X is a constant

X has no type

Answer

Correct Answer: You cannot assign a Double to a variable of type Int

Note: This Question is unanswered, help us to find answer for this one

18. What data type is this an example of? let vals = ("val", 1)

A dictionary

A tuple

An optional

This code contains error

Answer

Correct Answer: A tuple

Note: This Question is unanswered, help us to find answer for this one

19. Which of these choices is associated with unit testing?

XCTest

All of these answers

@testable

XCAssert

Answer

Correct Answer: All of these answers

Note: This Question is unanswered, help us to find answer for this one

20. What is wrong with this code? for (key, value) in [1: "one", 2: "two"]{print(key, value)}

The interaction source is invalid

The interaction variable is invalid

There is nothing wrong with this code

The comma in the print is misplaced

Answer

Correct Answer: There is nothing wrong with this code

Note: This Question is unanswered, help us to find answer for this one

21. In the function below, what are this and toThat examples of? func add(this x: Int, toThat y: Int)->{}

None of these answers

Local terms

Argument labels

Parameters names

Answer

Correct Answer: Argument labels

Note: This Question is unanswered, help us to find answer for this one

22. How do you designated a failable initializer?

You cannot

Deinit

Init?

Init

Answer

Correct Answer: Init?

Note: This Question is unanswered, help us to find answer for this one

23. How would you call a function that throws errors and also returns a value?

!try

Try?

Try!

?try

Answer

Correct Answer: Try?

Note: This Question is unanswered, help us to find answer for this one

24. What is the inferred type of x? let x = ["a", "b", "c"]

String[]

Array

Set

Array

Answer

Correct Answer: Array

Note: This Question is unanswered, help us to find answer for this one

25. Which object allows you access to specify that a block of code runs in a background thread?

DispatchQueue.visible

DispatchQueue.global

ErrorExample need to be labeled as throws.

DispatchQueue.background

Answer

Correct Answer: DispatchQueue.global

Note: This Question is unanswered, help us to find answer for this one

26. What must a convenience initializer call?

A base class convenience initializer

Either a designated or another convenience initializer

A designated initializer

None of these answers

Answer

Correct Answer: A designated initializer

Note: This Question is unanswered, help us to find answer for this one

27. What is the base class in this code? class LSN : MMM {}

MMM

LSN

There is no base class.

This code is invalid.

Answer

Correct Answer: MMM

Note: This Question is unanswered, help us to find answer for this one

28. What is the value of test after this code executes? let vt = (name: "ABC", val: 5) let test = vt.0

ABC

Name

Answer

Correct Answer: ABC

Note: This Question is unanswered, help us to find answer for this one

29. What is the value of t after this code is executed? let names = ["Larry", "Sven", "Bear"] let t = names.enumerated().first().offset

This code is invalid.

This code does not compile.

Larry

Answer

Correct Answer: This code is invalid.
This code does not compile.

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

30. What can AnyObject represent?

An instance of any class

An instance of function type

All of these answers

An instance of an optional type

Answer

Correct Answer: All of these answers

Note: This Question is unanswered, help us to find answer for this one

31. How many times will this loop be executed? for i in 0...100 {print(i)}

101

100

Answer

Correct Answer: 101

Note: This Question is unanswered, help us to find answer for this one

32. What is the correct way to add a value to this array? var strings = [1, 2, 3]

All of these answers

Strings.append(4)

Strings.insert(5, at: 1)

Strings += [5]

Answer

Correct Answer: All of these answers

Note: This Question is unanswered, help us to find answer for this one

33. All value types in Swift are _ under the hood?

Structs

Classes

Optionals

Generics

Answer

Correct Answer: Structs

Note: This Question is unanswered, help us to find answer for this one

34. How do you reference class members from within a class?

Self

Instance

Class

This

Answer

Correct Answer: Self

Note: This Question is unanswered, help us to find answer for this one

35. Which code snippet correctly creates a typealias closure?

Typealias CustomClosure: () -> ()

Typealias CustomClosure { () -> () }

Typealias CustomClosure -> () -> ()

Typealias CustomClosure -> () {}

Answer

Correct Answer: Typealias CustomClosure: () -> ()

Note: This Question is unanswered, help us to find answer for this one

36. What is wrong with this code? if let s = String.init("some string") { print(s)}

This String initializer does not return an optional.

String does not have an initializer that can take a String.

= is not a comparison.

Nothing is wrong with this code

Answer

Correct Answer: This String initializer does not return an optional.

Note: This Question is unanswered, help us to find answer for this one

37. How can you avoid a strong reference cycle in a closure?

Use a capture list to set class instances of weak or unowned.

You can't, there will always be a danger of strong reference cycles inside a closure.

Initialize the closure as read-only.

Declare the closure variable as lazy.

Answer

Correct Answer: Use a capture list to set class instances of weak or unowned.

Note: This Question is unanswered, help us to find answer for this one

38. How many values does vals have after this code is executed? var vals = Set = ["4", "5", "6"] vals.insert("5")

Three

Four

Eight

This code contains an error.

Answer

Correct Answer: This code contains an error.

Note: This Question is unanswered, help us to find answer for this one

39. DidSet and willSet are examples of _?

Property observers

Key properties

All of these answers

NewOld value calls

Answer

Correct Answer: Property observers

Note: This Question is unanswered, help us to find answer for this one

40. What describes this line of code? let val = 5

A constant named val of type Int

A variable named val of type item

A constant named val of type Number

A variable named val of type Int

Answer

Correct Answer: A constant named val of type Int

Note: This Question is unanswered, help us to find answer for this one

41. When a function takes a closure as a parameter, when do you want to mark is as escaping?

When it's executed after the function returns

When it's scope is undefined

When it's lazy loaded

All of these answers

Answer

Correct Answer: When it's executed after the function returns

Note: This Question is unanswered, help us to find answer for this one

42. What is the type of value1 in this code? let value1 = "\("test".count)"

String

Int

Null

Test.count

Answer

Correct Answer: String

Note: This Question is unanswered, help us to find answer for this one

43. The Codable protocol is _?

A combination of Encodable and Decodable

Not a true protocol <<<<---Possibly correct as it's a typealias of Encodable and Decodable

Required of all classes

Automatically included in all classes

Answer

Correct Answer: A combination of Encodable and Decodable

Note: This Question is unanswered, help us to find answer for this one

44. What is the correct way to call this function? func myFunc(_ a: Int, b: Int) -> Int {return a + b}

MyFunc(5, b: 6)

MyFunc(5, 6)

MyFunc(a: 5, b: 6)

MyFunc(a, b)

Answer

Correct Answer: MyFunc(5, b: 6)

Note: This Question is unanswered, help us to find answer for this one

45. What is the type of this function? func add(a: Int, b: Int) -> Int { return a+b }

Int

(Int, Int) -> Int

Int

Functions don't have types.

Answer

Correct Answer: (Int, Int) -> Int

Note: This Question is unanswered, help us to find answer for this one

46. What is the value of y? var x: Int? let y = x ?? 5

Nil

This code contains an error

Answer

Correct Answer: 5

Note: This Question is unanswered, help us to find answer for this one

47. What is the value of test in this code? var test = 1 == 1

TRUE

YES

This code contains an error

Answer

Correct Answer: TRUE

Note: This Question is unanswered, help us to find answer for this one

48. What is the value of y? let x = ["1", "2"].dropFirst() let y = x[0]

This code contains an error

Nil

Answer

Correct Answer: This code contains an error

Note: This Question is unanswered, help us to find answer for this one

49. Why is dispatchGroup used in certain situations?

It allows multiple synchronous or asynchronous operations to run on different queues.

It allows track and control execution of multiple operations together.

It allows operations to wait for each other as desired.

All of these answers.

Answer

Correct Answer: All of these answers.

Note: This Question is unanswered, help us to find answer for this one

50. What is the raw/underlying type of this enum? enum Direction {case north, south, east, west}

There is none.

String

Any

Int

Answer

Correct Answer: There is none.

Note: This Question is unanswered, help us to find answer for this one

51. What is the error in this code? let x = 5; guard x == 5 { return }

The guard is missing the else.

Nothing is wrong.

The guard is missing a then.

The comparison is wrong.

Answer

Correct Answer: The guard is missing the else.

Note: This Question is unanswered, help us to find answer for this one

52. What is this code an example of? let val = (Double)6

A syntax issue

Typecasting

Assignment

Initialization

Answer

Correct Answer: A syntax issue

Note: This Question is unanswered, help us to find answer for this one

53. Typical range of type Int8 is __

0 to 255

-128 to 127

-2147483648 to 2147483647

0 to 4294967295

Answer

Correct Answer: -128 to 127

Note: This Question is unanswered, help us to find answer for this one

54. The following are unordered collection types:

Array

Dictionary

Set

Dictionary and Set

Answer

Correct Answer: Dictionary and Set

Note: This Question is unanswered, help us to find answer for this one

55. A sequence of characters surrounded by double quotes is called _____?

String Literal

Special Character

Literal Expression

Bool Literal

Answer

Correct Answer: String Literal

Note: This Question is unanswered, help us to find answer for this one

56. Can cyclical relationships exist in value types?

Yes

Answer

Correct Answer: No

Note: This Question is unanswered, help us to find answer for this one

57. A closure is a function without a name.

True

False

Answer

Correct Answer: True

Note: This Question is unanswered, help us to find answer for this one

58.
var varB = 3.14159ng is the c
varB is inferred to be of type _____

Float

Double

Answer

Correct Answer: Double

Note: This Question is unanswered, help us to find answer for this one

59. print(myStr) What will be the output of the above code snippet in Swift4?

Hello World!

Hello

World!

Compiler error

Answer

Correct Answer: Hello
World!

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

60.
var myVar = 100
myVar = "Hello World"
print(varA)
The output will be

100

Hello World

Compile time error

Answer

Correct Answer: Compile time error

Note: This Question is unanswered, help us to find answer for this one

61. We can create an array of any type

True

False

Answer

Correct Answer: True

Note: This Question is unanswered, help us to find answer for this one

62. Which is the correct naming scheme for an Objective-C bridging header file into Swift project

ProjectName-Header-Bridging.h

ProjectName-Bridging-Header.h

ObjectiveC-Bridging-Header.h

All of the above

Answer

Correct Answer: ProjectName-Bridging-Header.h

Note: This Question is unanswered, help us to find answer for this one

63. Bridging header file will not be compiled due to the following issues:

Incorrect file naming convention

Missing file path in build settings

Both

It will be compiled anyway

Answer

Correct Answer: Both

Note: This Question is unanswered, help us to find answer for this one

64. Objective-C class factory methods will change into _____ after importing to Swift

Class method

Initializer

Convenience initializer

Properties

Answer

Correct Answer: Convenience initializer

Note: This Question is unanswered, help us to find answer for this one

65. Overriding functionality is possible using extension

True

False

Answer

Correct Answer: True

Note: This Question is unanswered, help us to find answer for this one

66. New initializers can be provided using extension

True

False

Answer

Correct Answer: True

Note: This Question is unanswered, help us to find answer for this one

67. What is the correct way to import an Objective-C class into bridging header file?

import CustomObject.h

#import "CustomObject.h"

import CustomObject

#import CustomObject.h

Answer

Correct Answer: #import "CustomObject.h"

Note: This Question is unanswered, help us to find answer for this one

68.
The following are collection types in Swift
Note: There may be more than one right answer.

String

Array

Dictionary

Set

Answer

Correct Answer: String
Array
Dictionary
Set

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

69.
var myName: Int = "John Doe"
print(myName)
The output will be

Some random Int generated by the compiler.

John Doe

Compile-time error

Answer

Correct Answer: Compile-time error

Note: This Question is unanswered, help us to find answer for this one

70.
The 'let' keyword is considered as:
Note: There may be more than one right answer.

Constant

read only

Thread safe

none

Answer

Correct Answer: Constant
read only
Thread safe

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

71. How can you create a new name for an existing type in Swift?

using extension

By inheritance

Overriding

Typealias

Answer

Correct Answer: Typealias

Note: This Question is unanswered, help us to find answer for this one

72.
In Swift, private properties of a class can be accessed in any of it's extension.

True

False

Answer

Correct Answer: False

Note: This Question is unanswered, help us to find answer for this one

73. Can you pass Int to a String type variable?

True

False

Answer

Correct Answer: False

Note: This Question is unanswered, help us to find answer for this one

74. Which of the following do you need to serialize and archive your custom types in Swift?

Subclass NSObject

Implement the NSCoding protocol

Subclass NSObject and implement the NSCoding protocol

Implement the Codable protocol

Answer

Correct Answer: Implement the Codable protocol

Note: This Question is unanswered, help us to find answer for this one

75. Stage when memory returned to stack or heap?

Deinitialization

Deallocation

Both

None

Answer

Correct Answer: Deallocation

Note: This Question is unanswered, help us to find answer for this one

76. During which stage memory is taken from stack or heap?

Initialization

Allocation

Both

None

Answer

Correct Answer: Allocation

Note: This Question is unanswered, help us to find answer for this one

77. What is the typical byte width of Float data type in Swift?

4 bytes

8 bytes

16 bytes

32 bytes

Answer

Correct Answer: 4 bytes

Note: This Question is unanswered, help us to find answer for this one

78. Weak references are declared as _____ types

Optional

Non optional

Constant

Static

Answer

Correct Answer: Optional

Note: This Question is unanswered, help us to find answer for this one

79. unowned reference types are declared as __

Optional

Non-optional

Constant

Static

Answer

Correct Answer: Non-optional

Note: This Question is unanswered, help us to find answer for this one

80. NSOperationQueue.mainQueue().addOperationWithBlock will add the operation to

Background thread

UI Thread

Answer

Correct Answer: UI Thread

Note: This Question is unanswered, help us to find answer for this one

81. GCD provides the following types of Queues:

Main Queue

Custom Queues

Global Queues

All of the above

Answer

Correct Answer: All of the above

Note: This Question is unanswered, help us to find answer for this one

82. NSOperationQueue conforms to

FIFO

LIFO

None

Answer

Correct Answer: None

Note: This Question is unanswered, help us to find answer for this one

83. GCD can dispatch a task

Synchronously

Asynchronously

Both

None

Answer

Correct Answer: Both

Note: This Question is unanswered, help us to find answer for this one

84.
func addStudent(_ student: Student) {
  concurrentStudentQueue.async(flags: .barrier) {
self._students.append(student)
DispatchQueue.main.async { //
  self.postContentAddedNotification()
}
  }
}
The code will ensure that the submitted DispatchWorkItem will be executed in parallel with any other DispatchWorkItem in the same queue.

True

False

Answer

Correct Answer: False

Note: This Question is unanswered, help us to find answer for this one

85. GCD conforms with the ____ order.

FIFO

LIFO

None

Answer

Correct Answer: FIFO

Note: This Question is unanswered, help us to find answer for this one

86. A Switch statement cannot handle String.

True

False

Answer

Correct Answer: False

Note: This Question is unanswered, help us to find answer for this one

87. In which data types can you define methods?

Class

Structure

Enumeration

All

Answer

Correct Answer: All

Note: This Question is unanswered, help us to find answer for this one

88. Swift allows you to write semicolons at the end of statement.

True

False

Answer

Correct Answer: True

Note: This Question is unanswered, help us to find answer for this one

89. If C is a superset of D, then D is a subset of C

True

False

Answer

Correct Answer: True

Note: This Question is unanswered, help us to find answer for this one

90. Which is true about the Dictionary?

All of the keys should be of same type

All of the values should be of same type

Keys and Values can be of different types

None

Answer

Correct Answer: Keys and Values can be of different types

Note: This Question is unanswered, help us to find answer for this one

91.
Extension can be used to create a new nested type of the following:
Note: There may be more than one right answer.

Class

Structure

Enumeration

Extension doesn't support nested types

Answer

Correct Answer: Class
Structure
Enumeration

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

92. Instance methods can be _____ in extension

Overloaded

Overriden

Mutating

None

Answer

Correct Answer: Mutating

Note: This Question is unanswered, help us to find answer for this one

93.
Which of the following are true about extension functionalities?
Note: There may be more than one right answer.

They Can define instance and type methods.

They Can define subscripts

They Can define and use new nested types

None

Answer

Correct Answer: They Can define instance and type methods.
They Can define subscripts
They Can define and use new nested types

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

94.
extension Int {
   subscript(var myInt: Int) -> Int {
  var no1 = 1
  while myInt > 0 {
     no1 *= 10
     --myInt
  }
  return (self / no1) % 10
   }
}
print(12[0])
What is the output?

Answer

Correct Answer:

Note: This Question is unanswered, help us to find answer for this one

95.
After importing Objective-C code to Swift, the above method will be imported as
(instancetype)initWithFrame:(CGRect)frame
style:(UITableViewStyle)style;

initWithFrame(frame: CGRect, style: UITableViewStyle) { }

initWith(frame: CGRect, style: UITableViewStyle) { }

init(frame: CGRect, style: UITableViewStyle) { }

init(frame: CGRect, And style: UITableViewStyle) { }

Answer

Correct Answer: init(frame: CGRect, style: UITableViewStyle) { }

Note: This Question is unanswered, help us to find answer for this one

96. Objective-C class can be instantiated in Swift class only through

Objective-C initializer syntax.

Swift initializer syntax.

All

Answer

Correct Answer: Swift initializer syntax.

Note: This Question is unanswered, help us to find answer for this one

97. Objective-C nullable properties will appear as __ properties when imported to Swift project.

Constant

optional

non-optional

Answer

Correct Answer: optional

Note: This Question is unanswered, help us to find answer for this one

98. Closures capture ____ reference of objects by default

Weak

Strong

unowned

None

Answer

Correct Answer: Strong

Note: This Question is unanswered, help us to find answer for this one

99. Please check following code and tell what can be problem? import UIKitvarintVar:Int?=3 intVar = nil varstrVar:StringstrVar = nil

varintVardecalaration is incorrect

strVar cannot be initialized with nil

intVar cannot be initialized with nil

everything is ok

Answer

Correct Answer: strVar cannot be initialized with nil

Note: This Question is unanswered, help us to find answer for this one

100. What does Swift compile to?

C++

java

Objective-C

Machine Code

Answer

Correct Answer: Machine Code

Note: This Question is unanswered, help us to find answer for this one

101.
What is the correct way to import Objective-C files into Swift?

Objective-C classes are automatically imported.

Objective-C classes are imported in the Swift file using the class.

Objective-C classes are imported via a Bridging Header.

Objective-C classes import themselves by declare @SwiftImportable.

Answer

Correct Answer: Objective-C classes are imported via a Bridging Header.

Note: This Question is unanswered, help us to find answer for this one

102.
What is the return type of the following code? func nameFunc() -> String { return "Jhon" }

Double

String

Bool

Array

Answer

Correct Answer: String

Note: This Question is unanswered, help us to find answer for this one

103.
The following attribute can be used to allow a protocol to contain optional functions and to be used in ObjC?

objective_bridge

ObjC

_objc

@objc

Answer

Correct Answer: @objc

Note: This Question is unanswered, help us to find answer for this one

104.
Suppose below variable declaration, select a right answer? import UIKit var str = "string" var ŝanĝiĝema = "хувьсагч" var & = "&"

2nd declaration is invalid

3rd declaration is invalid

Both is correct

None of the above

Answer

Correct Answer: 3rd declaration is invalid

Note: This Question is unanswered, help us to find answer for this one

105.
How can you fix the missing characters for the following code? func userScore -> Bool { return true }

{}

()

[]

{}-> Bool

Answer

Correct Answer: ()

Note: This Question is unanswered, help us to find answer for this one

106.
How to hide status bar in iOS app with Swift as follows?

We need to change info.plist file to hide status bar

We need override prefersStatusBarHidden() function on the view controller to return true always

We need set UIApplication.sharedApplication().statusBarHidden=true; with viewWillAppear() function overriding

There is no way to hide it with swift, we need to combine Objective C functions -WRONG ANS

Answer

Correct Answer: We need set UIApplication.sharedApplication().statusBarHidden=true; with viewWillAppear() function overriding

Note: This Question is unanswered, help us to find answer for this one

107.
Which of the following is an appropriate syntax for dispatching a heavy operation to a background thread?

dispatch_async(DISPATCH_QUEUE_PRIORITY_BACKGROUND), { self.heavyOperation() })

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), { self.heavyOperation() })

DISPATCH_QUEUE_PRIORITY_BACKGROUND({ self.heavyOperation() })

dispatch_async({ self.heavyOperation() })

Answer

Correct Answer: dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), { self.heavyOperation() })

Note: This Question is unanswered, help us to find answer for this one

108.
If a class is named 'MyClass' with a nested enum called 'Status', how do you indicate that a variable is an enum of type 'Status' outside the context of 'MyClass'? class MyClass { enum Status { case On, Off } }

var status: MyClass.Status = .On

var status: Status = .On

var status: MyClass<Status> = .On

var status: MyClass(Status) = .On

Answer

Correct Answer: var status: MyClass.Status = .On

Note: This Question is unanswered, help us to find answer for this one

109.
What is the output when following code is executed? import UIKit import AVFoundation var p: AVAudioPlayer? func func(filename:String) { let url = NSBundle.mainBundle().URLForResource(filename, withExtension: "caf")! do { p = try AVAudioPlayer(contentsOfURL: url) guard let p = p else { return } … … … p.prepareToPlay() p.play() } catch let error as NSError { print(error.description) } }

Plays audio file given as parameter in current folder

Plays audio caf file in the resource folder of the bundle

Plays audio mp3 file in the Contents folder of the bundle

Function cannot be run and will output exception error

Answer

Correct Answer: Plays audio caf file in the resource folder of the bundle

Note: This Question is unanswered, help us to find answer for this one

110.
Based on var index = UInt8.max, which of the following operation results to the value of zero for var index?

index = index &- 1

index = index &+ 1

index = index &* 1

index = index &/ 255

Answer

Correct Answer: index = index &+ 1

Note: This Question is unanswered, help us to find answer for this one

111.
Which of the following is the correct keyword for defining a constant in Swift?

const

contant

final

let

def

Answer

Correct Answer: let

Note: This Question is unanswered, help us to find answer for this one

112.
The following keyword in the context of a Switch statement is required to force the execution of a subsequent case?

fallthrough

continue

break

return

Answer

Correct Answer: fallthrough

Note: This Question is unanswered, help us to find answer for this one

113.
Which of the following statements is a valid way to extend the capabilities of our theoretical class, MyClass to conform to protocol MyProtocol?

extension MyClass(MyProtocol) { }

extension MyClass, prot MyProtocol { }

extension MyClass: MyProtocol { }

extension MyClass, MyProtocol { }

Answer

Correct Answer: extension MyClass: MyProtocol { }

Note: This Question is unanswered, help us to find answer for this one

114.
In Swift, objects are usually references to instances for both _____ and classes?

composite

structures

interface

compound

Answer

Correct Answer: structures

Note: This Question is unanswered, help us to find answer for this one

115.
What is the return value of the type check operator - is ?

true, false

0, 1

yes, no

1, -1

Answer

Correct Answer: true, false

Note: This Question is unanswered, help us to find answer for this one

116.
Which integer literals have a decimal value of 17? (choose all that apply)

let decimalInteger = 17

let binaryInteger = 0b1001

let octalInteger = 0o21

let hexadecimalInteger = 0x11

Answer

Correct Answer: let decimalInteger = 17
let octalInteger = 0o21
let hexadecimalInteger = 0x11

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

117.
What is the correct way to declare Decomposed Tuple?

var rectangle = (x:0, y:0, width:20, height:50)

let (a, b, c, d) = rectangle

var (e, _, _, _) = rectangle

var rectangle = (x:0, y:0, width:20, height:50)

Answer

Correct Answer: let (a, b, c, d) = rectangle

Note: This Question is unanswered, help us to find answer for this one

118.
How do you remove items from arrays? (choose all that apply)

arry.removeLast()

arry.removeAtIndex(0)

arry.removeAll(keepCapacity: false)

None of the above

Answer

Correct Answer: arry.removeLast()
arry.removeAtIndex(0)
arry.removeAll(keepCapacity: false)

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

119.
What are the Numeric Integer Literals? (choose all that apply)

A decimal number, with no prefix

A binary number, with a 0b prefix

An octal number, with a 0o prefix

A hexadecimal number, with a 0x prefix

None of the above

Answer

Correct Answer: A decimal number, with no prefix
A binary number, with a 0b prefix
An octal number, with a 0o prefix
A hexadecimal number, with a 0x prefix

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

120.
Which of the following is a correct answer for Enumerations?

Enumerations can define initializers.

Enumerations cannot conform to protocols.

Enumerations can conform to protocols.

Answer

Correct Answer: Enumerations can define initializers.

Note: This Question is unanswered, help us to find answer for this one

121.
How to extract a string from URL data?

import UIKit var url = "http://www.google.com/ss.js?id=123456789"; var id = url.componentsSeparatedByString("id="); print(id[1]) ;

var url = "http://www.google.com/ss.js?id=123456789;"; let hd = "http://www.google.com/ss.js?"; let ln = hd.text.characters.count; let id: String = url.startIndex.advancedBy(ln); print(id) ;

var url:String = "http://www.google.com/ss.js?id=123456789"; let hd = "http://www.google.com/ss.js?" ; let ln = hd.lengthOfBytesUsingEncoding(NSUTF16StringEncoding); let id: String = url.startIndex.advancedBy(ln); print(id) ;

All of the above

Answer

Correct Answer: import UIKit var url = "http://www.google.com/ss.js?id=123456789"; var id = url.componentsSeparatedByString("id="); print(id[1]) ;

Note: This Question is unanswered, help us to find answer for this one

122.
Which of the following statements are true about Tuple?

Group multiple values of any type into a single compound value

Values can be accessed by index

Tuples can have named values

All of the above

Answer

Correct Answer: Group multiple values of any type into a single compound value

Note: This Question is unanswered, help us to find answer for this one

123.
In Swift, what are the benefits of classes?

Inheritance acquires the properties of one class to another class

Type casting enables the user to check class type at run time

Deinitializers take care of releasing memory resources

Reference counting allows the class instance to have more than one reference

All of the above

Answer

Correct Answer: All of the above

Note: This Question is unanswered, help us to find answer for this one

124.
When the following code is executed, what it will do? funcfunc() { let layer = UIApplication.sharedApplication().keyWindow!.layer let scale = UIScreen.mainScreen().scale UIGraphicsBeginImageContextWithOptions(layer.frame.size, false, scale); layer.renderInContext(UIGraphicsGetCurrentContext()!) let s = UIGraphicsGetImageFromCurrentImageContext() UIGraphicsEndImageContext() UIImageWriteToSavedPhotosAlbum(s, nil, nil, nil) }

It gets handle of the application screen and saves its screenshot

It gets full screenshot and will save it as JPG file in photo folder

It gets topmost app screenshot and saves it in the temp folder

It gets load but won't save

Answer

Correct Answer: It gets full screenshot and will save it as JPG file in photo folder

Note: This Question is unanswered, help us to find answer for this one

125.
Select the most proper answer. import UIKit import AVFoundation … … … let r:AVAudioRecorder? do { r = try AVAudioRecorder(URL: soundFileURL, settings: rSettings) r.delegate = self r.meteringEnabled = true r.prepareToRecord() } catch let error as NSError { r = nil print(error.localizedDescription) }

It opens audio recording device and captures audio file as rSettings

It opens audio recording file, and prepares for the audio recording environment

It opens audio file and loads audio device driver

It opens audio and saves file on the server

Answer

Correct Answer: It opens audio recording file, and prepares for the audio recording environment

Note: This Question is unanswered, help us to find answer for this one

126.
What is the need for having structures?

To encapsulate simple data values.

To copy the encapsulated data and its associated properties by 'values' rather than by 'references'.

Structure to 'Copy' and 'Reference'.

All of them

Answer

Correct Answer: All of them

Note: This Question is unanswered, help us to find answer for this one

127.
In Swift, what's the correct way variables consist?

var> name > type > value

var> type > name > value

var> type > name > type

var> value > type > name

Answer

Correct Answer: var> name > type > value

Note: This Question is unanswered, help us to find answer for this one

128.
On which tag background color for the page can be set?

<head>

<body>

<font>

<page>

Answer

Correct Answer: <body>

Note: This Question is unanswered, help us to find answer for this one

129.
Compare the below code and what will result?

import UIKit

var rank:Dictionary = [1:”First”, 2: “Second”, 3: “Third”];

rank.updateValue(“Forth”, forKey: 4);

rank[5]=”Fifth”;

for I in rank {

print(i);

}

import UIKit

var rank:Dictionary = [2:”Second”, 1: “First”, 3: “Third”];

rank[5]=”Fifth”;

rank.updateValue(“Forth”, forKey: 4);

for I in rank {

print(i)

}

Output will be different in order

Output Result will be same

Nothing can be output

Answer

Correct Answer: Output Result will be same

Note: This Question is unanswered, help us to find answer for this one

130.
Please check following code and tell what can be problem?

import UIKit ;

var intVar:Int?=3;

intVar = nil;

var strVar:String;

strVar = nil;

var intVar decalaration is incorrect

intVar cannot be initialized with nil

strVar cannot be initialized with nil

everything is ok

Answer

Correct Answer: strVar cannot be initialized with nil

Note: This Question is unanswered, help us to find answer for this one

131.
Execute below code and tell what can be problem? import UIKit let fm = NSFileManager.defaultManager() fm.removeItemAtPath("file.old")

it will work

If it cannot find file, exception would be occurred, we need exception handling

If it cannot find file, exception would be occurred, but we need not exception handling because Swift itself can process it internally

We cannot use NSFileManager object because it’s Objective C language

Answer

Correct Answer: If it cannot find file, exception would be occurred, we need exception handling

Note: This Question is unanswered, help us to find answer for this one

132.
Use the classes defined above to create a new Person instance, and try to access its numberOfRooms property as before?

let john = Person() if roomCount = john.residence?.numberOfRooms { println("John's residence has \(roomCount) room(s).") }else{ println("Unable to retrieve the number of rooms.") }

let john = Person() if let roomCount = john.residence?.numberOfRooms { println("John's residence has \(roomCount) room(s).") }else{ println("Unable to retrieve the number of rooms.") }

let john = Person() if roomCount = john-let.residence?.numberOfRooms { println("John's residence has \(roomCount) room(s).") }else{ println("Unable to retrieve the number of rooms.") }

john = Person() if roomCount = john-let.residence?.numberOfRooms { println("John's residence has \(roomCount) room(s).") }else{ println("Unable to retrieve the number of rooms.") }

Answer

Correct Answer: let john = Person() if let roomCount = john.residence?.numberOfRooms { println("John's residence has \(roomCount) room(s).") }else{ println("Unable to retrieve the number of rooms.") }

Note: This Question is unanswered, help us to find answer for this one

133.
What does the following code?

import UIKit

var str1:String?="text1";

var str2:String="text2";

var int1:Int?=111;

var int2:Int=222;

var array:String[] = [str1, str2, int1, int2];

array=[];

array cannot be initialized due to another data type variables.

Str1 and int1 cannot be initialized because they are optional variables.

Str2 and int2 cannot be initialized because they are not optional variables.

Array=[] is invalid command

Answer

Correct Answer: Str2 and int2 cannot be initialized because they are not optional variables.

Note: This Question is unanswered, help us to find answer for this one

134.
Extensions can add new instance ____?

methods

type module

variable

Answer

Correct Answer: methods

Note: This Question is unanswered, help us to find answer for this one

135.
Consider the following code output when the file doesn’t exist?

import UIKit

let filename:String = "testfile";

var readdata:String = "test data";

let pathname = NSURL(fileURLWithPath: "..") URLByAppendingPathComponent(filename) ;

do {

readdata = try NSString(contentsOfURL: pathname, encoding:NSUTF8StringEncoding) as String } catch { print("read error")

}

print(readdata);

read error

test data

test file

None of the above

Answer

Correct Answer: read error
test data

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

136.
How to convert string into integer value? import UIKit let str_number = "320"

let int1_value = Int(str_number)

let int2_value = (str_number as NSString).integerValue

let int3_value = str_number.integerValue

let int4_value = atoi(str_number as String)

Answer

Correct Answer: let int1_value = Int(str_number)
let int2_value = (str_number as NSString).integerValue
let int4_value = atoi(str_number as String)

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

137.
Choose the correct answer?

import Foundation

import AVFoundation

func startCapture()

{ if let device : AVCaptureDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeAudio){ do { self.session = AVCaptureSession() try device.lockForConfiguration() let audioInput = try AVCaptureDeviceInput(device: device) device.unlockForConfiguration() // audio capture operation … … } catch { } } }

Everything is Ok

If AVFoundation was not imported, it will not work

If audio capture device or device driver was not prepared, exception will occurred.

If audio device was already used, this function cannot work

Answer

Correct Answer: If AVFoundation was not imported, it will not work
If audio device was already used, this function cannot work

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

138.
Following code which is super class? class X: Y { let str:String let val:Int? … init() { … } deinit(){ … } }

X is a superclass of Y

Y is a super class of X

it doesn’t use class

X and Y is parent class

Answer

Correct Answer: Y is a super class of X

Note: This Question is unanswered, help us to find answer for this one

139.
How to get local IP address in swift?

GetAdapterInfo

getnameinfo

socket

getIP()

Answer

Correct Answer: getnameinfo
getIP()

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

140.
Read the following code and select output?

import UIKit

var array:[String] = ["string1", "string2"];

print("array list has (array.count) items.");

array list has (array.count) items.

array list has 2 items

array list has 2

array list has 4

Answer

Correct Answer: array list has (array.count) items.

Note: This Question is unanswered, help us to find answer for this one

141.
What is the output when following statement is executed?

import UIKit

let filename:String = "test.dat";

let write_data:String = "write data";

var read_data:String = "read data";

if let directory = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.AllDomainsMask, true).first

{

            let pathname =            NSURL(fileURLWithPath:directory).URLByAppendingPathComponent(filename);

            do {

                        try

                                    write_data.writeToURL(pathname, atomically: false, encoding: N            SUTF8StringEncoding) }

            catch { print(“write error”) }

//reading

do

{ read_data = try NSString(contentsOfURL: pathname, encoding: NSUTF8StringEncoding) as String } catch

{ print(“read error”) } print(read_data) }

Write error

write data

read data

read error

Answer

Correct Answer: write data

Note: This Question is unanswered, help us to find answer for this one

142.
The structure of a value or ____ value?

composite

default

pattern

struct

Answer

Correct Answer: struct

Note: This Question is unanswered, help us to find answer for this one

143.
How to compare below 2 strings? let str1 = "string1" let str2 = "string2”

if str1 == str2

if str1.isEqual(str2)

if([[self.str1 string] isEqualToString:str2]

None of the above

Answer

Correct Answer: if str1 == str2

Note: This Question is unanswered, help us to find answer for this one

144.
Which of the following is safest for downcasting?

as!

is?

as?

Answer

Correct Answer: as?

Note: This Question is unanswered, help us to find answer for this one

145.
If the following code executed what can be problem?

import UIKit

func MinMax(array: [Int]) -> (min: Int, max: Int)

{

            var min = array[0];

            var max = array[0];

            for val in array[1..<array.count] {

            if val< min { min = val }

            else if val> max { max = val }

            }

            return (min, max)

}

Function has no problem

min and max variables were re-defined inside the function

min and max variables should be defined as optional variables

array.count should be placed with array.count()

Answer

Correct Answer: min and max variables should be defined as optional variables

Note: This Question is unanswered, help us to find answer for this one

146.
What will be the output of the following code snippet? let val1 = "Hello," let val2 = "World!" var result = val1 \ val2 print( result )

Hello,World!

Compiler Error

Hello, \ World!

Answer

Correct Answer: Compiler Error

Note: This Question is unanswered, help us to find answer for this one

147.
A while loop performs a set of statements until a condition becomes false. These kinds of loops are best used when the number of iterations is not known before the first iteration begins. Swift provides two kinds of while loops?

while evaluates its condition at the start of each pass through the loop.

repeat-while evaluates its condition at the end of each pass through the loop.

end while evaluates its condition at the start of each pass through the loop.

All of the above (1st two options are correct)

Answer

Correct Answer: All of the above (1st two options are correct)

Note: This Question is unanswered, help us to find answer for this one

148.
Closure expressions in Swift language follow crisp, optimization, and lightweight syntax styles which includes?

Inferring parameter and return value types from context.

Implicit returns from single-expression closures.

Shorthand argument names and

Trailing closure syntax

All of the them

Answer

Correct Answer: All of the them

Note: This Question is unanswered, help us to find answer for this one

149.
In Swift there are ____ kinds of types named and Compound?

single

two

many

None of the above

Answer

Correct Answer: two

Note: This Question is unanswered, help us to find answer for this one

150.
____ in Swift is implemented with the is and as operators. These two operators provide a simple and expressive way to check the type of a value or cast a value to a different type?

Operator

Optional Chaining

Type casting

Protocols

Answer

Correct Answer: Type casting

Note: This Question is unanswered, help us to find answer for this one

151.
ARC tracks how many , , and variables?

properties

constants

functions

All of the above

Answer

Correct Answer: properties
constants

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

152.
How to connect UI in Swift Language?

Same as like c-objective. There is no change in binding process only core level has been changed. You can choose button/label on xib file and binding as is it.

Same as like Java. There is no change in binding process only core level has been changed. You can choose button/label on xib file and binding as is it.

Same as like Perl. There is no change in binding process only core level has been changed. You can choose button/label on xib file and binding as is it.

All of the above

Answer

Correct Answer: Same as like c-objective. There is no change in binding process only core level has been changed. You can choose button/label on xib file and binding as is it.

Note: This Question is unanswered, help us to find answer for this one

153.
How to enumerate an enum with String type, using the following code?

Suit { case Spades, Hearts, Diamonds, Clubs func simpleDescription() -> String { switch self { case .Spades: return "spades" case .Hearts: return "hearts" case .Diamonds: return "diamonds" case .Clubs: return "clubs" } } }

ProductCategory : String { case Washers = "washers", Dryers = "dryers", Toasters = "toasters" static let allValues = [Washers, Dryers, Toasters] } for category in ProductCategory.allValues{ //Do something }

enum Suit { case Spades, Hearts, Diamonds, Clubs func simpleDescription() -> String { switch self { case .Spades: return "spades" case .Hearts: return "hearts" case .Diamonds: return "diamonds" case .Clubs: return "clubs" } } }

enum ProductCategory : String { case Washers = "washers", Dryers = "dryers", Toasters = "toasters" static let allValues = [Washers, Dryers, Toasters] } for category in ProductCategory.allValues{ //Do something }

Answer

Correct Answer: enum Suit { case Spades, Hearts, Diamonds, Clubs func simpleDescription() -> String { switch self { case .Spades: return "spades" case .Hearts: return "hearts" case .Diamonds: return "diamonds" case .Clubs: return "clubs" } } }

Note: This Question is unanswered, help us to find answer for this one

154.
Storing Swift value types in Core Data?

struct MyStruct { let x : Int let y : Bool let z : Double }

func valueToData<T>(var t: T) -> NSData { return NSData(bytes: &t, length: sizeof(T)) } func dataToValue<T>(inout t: T, data: NSData) { memcpy(&t, data.bytes, data.length) }

let originalValue = MyStruct(x: 3, y: true, z: 1.3) let data = valueToData(originalValue) var s = MyStruct(x: 0, y: false, z: 0) dataToValue(&s, data: data)

All of the above

Answer

Correct Answer: All of the above

Note: This Question is unanswered, help us to find answer for this one

155.
In Swift, a function is defined by the "____"?

function

func

public function

All of the above

Answer

Correct Answer: func

Note: This Question is unanswered, help us to find answer for this one

156.
Define Initializer Role for Stored Properties?

To create an initial value

To assign default property value within the property definition

To initialize an instance for a particular data type 'init()' is used

All of the above

Answer

Correct Answer: All of the above

Note: This Question is unanswered, help us to find answer for this one

157.
Delegation is a design pattern that enables _____?

class

function

variable

Answer

Correct Answer: class

Note: This Question is unanswered, help us to find answer for this one

158.
An __ defines a common type for a group of related values and enables you to work with those values in a type-safe way within your code?

enumeration

structures

classes

function

Answer

Correct Answer: enumeration

Note: This Question is unanswered, help us to find answer for this one

159.
Which of the following is not a valid data type in Swift?

Float

Bool

String

MovieClip

Answer

Correct Answer: MovieClip

Note: This Question is unanswered, help us to find answer for this one

160.
This represents a Boolean value which is either true or false?

Bool

Float

String

Optional

Answer

Correct Answer: Bool

Note: This Question is unanswered, help us to find answer for this one

161.
Which keyword is used to define a constant?

var

let

constant

All of the above

Answer

Correct Answer: let

Note: This Question is unanswered, help us to find answer for this one

162.
The example below defines two variables, movieCount and songCount, which count the number of Movie and Song instances in the library array?

var movieCount = 0 var songCount = 0 for item in library { if item is Movie { ++movieCount }else if item is Song { ++songCount } } println("Media library contains \(movieCount) movies and \ (songCount) songs")

var movieCount = 0 var songCount = 0 for item in library { if item is Movie { ++movieCount }else if item is Song { ++songCount } }

var movieCount = 0 var songCount = 0 for let in library { if let is Movie { ++movieCount }else if item is Song { ++songCount } } println("Media library contains \(movieCount) movies and \ (songCount) songs")

All of the above

Answer

Correct Answer: var movieCount = 0 var songCount = 0 for item in library { if item is Movie { ++movieCount }else if item is Song { ++songCount } } println("Media library contains \(movieCount) movies and \ (songCount) songs")

Note: This Question is unanswered, help us to find answer for this one

163.
Use func to declare a function. Call a function by following its name with a list of arguments in parentheses. Use -> to separate the parameter names and types from the function’s return type?

func greet(name: String, day: String) -> array { return "Hello \(name), today is \(day)." } greet("Bob", "Tuesday")

func greet(name: String, day: String) -> String { return "Hello \(name), today is \(day)." } greete("Bob", "Tuesday")

func greet(name: String, day: String) -> String { return "Hello \(name), today is \(day)." } greet("Bob", "Tuesday")

All of the above

Answer

Correct Answer: func greet(name: String, day: String) -> String { return "Hello \(name), today is \(day)." } greet("Bob", "Tuesday")

Note: This Question is unanswered, help us to find answer for this one

164.
__ can require that conforming types have specific instance properties, instance methods, type methods, operators, and subscripts?

Protocols

Extensions

Generics

Inheritance

Answer

Correct Answer: Protocols

Note: This Question is unanswered, help us to find answer for this one

165.
How do you save local storage data in a swift application?

struct defaultsKeys { static let keyOne = "firstStringKey" static let keyTwo = "secondStringKey" }

let defaults = NSUserDefaults.standardUserDefaults() defaults.setValue("Some String Value", forKey: defaultsKeys.keyOne) defaults.setValue("Another String Value", forKey: defaultsKeys.keyTwo) defaults.synchronize()

let defaults = NSUserDefaults.standardUserDefaults() if let stringOne = defaults.stringForKey(defaultsKeys.keyOne) { println(stringOne) // Some String Value } if let stringTwo = defaults.stringForKey(defaultsKeys.keyTwo) { println(stringTwo) // Another String Value }

All of the above

Answer

Correct Answer: All of the above

Note: This Question is unanswered, help us to find answer for this one

166.
How to get userinfo from NSNotification in swift 3?

func downloadProgress(notification:NSNotification){ if let userInfo = notification.userInfo as NSDictionary { print(userInfo) // [AnyHashable("progressPercentage"): 0.82530790852915281] if let progressValue = userInfo["progressPercentage"] as? Float { if progressValue > 0.01{ } } } }

func downloadProgress(notification:NSNotification){ if let userInfo = notification.userInfo as [String: Any] { print(userInfo) if let progressValue = userInfo["progressPercentage"] as? Float { if progressValue > 0.01{ } } } }

func downloadProgress(notification:NSNotification){ if let userInfo = notification.userid as NSDictionary { print(userInfo) // [AnyHashable("progressPercentage"): 0.82530790852915281] if let progressValue = userInfo["progressPercentage"] as? Float { if progressValue > 0.01{ } } } }

All of the them

Answer

Correct Answer: func downloadProgress(notification:NSNotification){ if let userInfo = notification.userInfo as [String: Any] { print(userInfo) if let progressValue = userInfo["progressPercentage"] as? Float { if progressValue > 0.01{ } } } }

Note: This Question is unanswered, help us to find answer for this one

167.
Protocols can be accessed as types in?

Function, method or initialize as a parameter or return type.

Constant, variable or property.

Arrays, dictionaries or other containers as items.

All of the above

Answer

Correct Answer: All of the above

Note: This Question is unanswered, help us to find answer for this one

168.
Swift has built-in support for checking _____ which ensures that you don’t accidentally use APIs that are unavailable on a given deployment target?

API availability

Land availability

Add availability

Block availability

Answer

Correct Answer: API availability

Note: This Question is unanswered, help us to find answer for this one

169.
List out what are the control transfer statements used in Swift?

Continue

Break

Fallthrough

Return

All of the above

Answer

Correct Answer: All of the above

Note: This Question is unanswered, help us to find answer for this one

170.
Swift Generics & Upcasting

class Fruit {} class Apple: Fruit {} class Orange: Fruit {} class Basket<T: Fruit> { private var items: [T] func add(item: T) { items.append(item) } init() {} } func addItem<T: Fruit>(var basket: Basket<T>, item: T) { basket.add(item) } let basket:Basket<Apple> = Basket() addItem(basket as Basket<Fruit>, Orange())

class Foo { } class Thing<T: Foo> { func produceBar() -> Bar { return Bar(aThing: self as! Thing<Foo>) } } class Bar { var thing: Thing<Foo> init(var aThing: Thing<Foo>) { self.thing = aThing } }

func addItem<T: Fruit>(var basket: Basket<T>, item: T) { basket.add(item) } let basket:Basket<Apple> = Basket() addItems(basket as Basket<Fruit>, Orange())

class Foo { } class Thing<T: Foo> { func produceBar() -> Bar { add Bar(aThing: self as! Thing<Foo>) } } class Bar { var thing: Thing<Foo> init(var aThing: Thing<Foo>) { blank.thing = aThing } }

Answer

Correct Answer: class Fruit {} class Apple: Fruit {} class Orange: Fruit {} class Basket<T: Fruit> { private var items: [T] func add(item: T) { items.append(item) } init() {} } func addItem<T: Fruit>(var basket: Basket<T>, item: T) { basket.add(item) } let basket:Basket<Apple> = Basket() addItem(basket as Basket<Fruit>, Orange())

Note: This Question is unanswered, help us to find answer for this one

171.
Tuples group multiple values into a single _____ value?

structure

constant

compound

All of the above

Answer

Correct Answer: compound

Note: This Question is unanswered, help us to find answer for this one

172.
What is Swift ?

Swift is Apple's latest programming language for iOS and OS X apps that builds on the best of C and Objective-C, without the constraints of C compatibility. Swift adopts safe programming patterns and adds modern features to make programming easier, and flexible.

Swift is Google latest programming language for iOS and OS X apps that builds on the best of C and Objective-C, without the constraints of C compatibility. Swift adopts safe programming patterns and adds modern features to make programming easier, and flexible.

Swift is Google latest programming language for Android and OS X apps that builds on the best of C and Objective-C, without the constraints of C compatibility. Swift adopts safe programming patterns and adds modern features to make programming easier, and flexible.

All of them

Answer

Correct Answer: Swift is Apple's latest programming language for iOS and OS X apps that builds on the best of C and Objective-C, without the constraints of C compatibility. Swift adopts safe programming patterns and adds modern features to make programming easier, and flexible.

Note: This Question is unanswered, help us to find answer for this one

173.
What is the difference between let and var in swift? let x = 10 var x = 10

A- let is used to declare a constant value you won't change.

B- var is used to decalre a variable value you could change it's value.

C- Both(A,B)

D- None of the above

Answer

Correct Answer: C- Both(A,B)

Note: This Question is unanswered, help us to find answer for this one

174.
How to hide status bar in ios app with Swift?

We need to change info.plist file to hide status bar

We need override prefersStatusBarHidden() function on the view controller to return true always

We need set UIApplication.sharedApplication().statusBarHidden=true; with viewWillAppear() function overriding

There is no way to hide it with swift, we need to combine Objective C functions

Answer

Correct Answer: We need override prefersStatusBarHidden() function on the view controller to return true always
We need set UIApplication.sharedApplication().statusBarHidden=true; with viewWillAppear() function overriding

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

175.
Which of is not a valid Access control in Swift?

public

protected

private

All of the above

Answer

Correct Answer: protected

Note: This Question is unanswered, help us to find answer for this one

176.
Initialization is the process of preparing an instance of a _____?

class

structure

enumeration

All of the above

Answer

Correct Answer: All of the above

Note: This Question is unanswered, help us to find answer for this one

177.
Restrict extensions on a type in Swift?

final class Person { func testFunc() {} } extension Person { func testFunc2() {} } let test = Person () test.testFunc2()

final class Person { private let name: String func tellName() -> String { return "I am \(name)" } init(name: String) { self.name = name } }

final class Person { func testFunc() {} } extensions Person { func testFunc2() {} } let test = Person () test.testFunc2()

final class Person { private let name func tellName() { return "I am \(name)" } init(name: String) { self.name = name } }

Answer

Correct Answer: final class Person { private let name: String func tellName() -> String { return "I am \(name)" } init(name: String) { self.name = name } }

Note: This Question is unanswered, help us to find answer for this one

178.
Which of the following True statments of Closures?

Closures are similar to blocks in C and Objective-C

Closures are enclosed in curly braces {}

Closures are first class type so it can be nested, return and passed as parameter

All of the above

Answer

Correct Answer: All of the above

Note: This Question is unanswered, help us to find answer for this one

179.
Shifting Behavior for Unsigned Integers?

Existing bits are moved to the left or right by the requested number of places.

Any bits that are moved beyond the bounds of the integer’s storage are discarded.

Zeros are inserted in the spaces left behind after the original bits are moved to the left or right.

Arrays, dictionaries or other containers as items.

Answer

Correct Answer: Existing bits are moved to the left or right by the requested number of places.
Any bits that are moved beyond the bounds of the integer’s storage are discarded.
Zeros are inserted in the spaces left behind after the original bits are moved to the left or right.

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

180.
What is Managing Memory in Swift?

In Swift with ARC we have no way to clean up the actual hardware ram. We can only make it possible for the OS to do that for us. One part is using the right code (optionals and weak) the other part is creating time for the OS to do it's job.

Imagine we have a function that runs on all threads indefinitely. It does one thing, load an image, convert to black/white and save. All images max at a couple of mb’s and the function creates no Software Memory Leaks. Because images don’t have a set size and might have different compression they don’t have the same footprint. This function will always crash your app.

This “Hardware” Memory Leak is caused by the function always taking the next available slot of memory.

The OS does not step in to “actually clean the memory” because there is no idle time. Putting a delay between each pass completely fixes this.

All of the above

Answer

Correct Answer: All of the above

Note: This Question is unanswered, help us to find answer for this one

181.
What will be the output of the following code snippet?

var ary1 = [1, 2, 3, 4];

var ary2 = ary1;

ary2.append(5);

var result = ary1.count;

Answer

Correct Answer: 4

Note: This Question is unanswered, help us to find answer for this one

182.
What are the features of Swift Programming?

It eliminates entire classes of unsafe code Variables are always initialized before use

Arrays and integers are checked for overflow

Memory is managed automatically

Instead of using “if” statement in conditional programming, swift has “switch” function

All of the above

Answer

Correct Answer: All of the above

Note: This Question is unanswered, help us to find answer for this one

183.
Which of the following could be used to indicate the Function Type of the following function: func joinStrings(stringOne: String, stringTwo: String) -> String { return stringOne + stringTwo }

func(String, String -> String)

(String, String) -> String

{String, String} -> String

{String, String}(String)

Answer

Correct Answer: (String, String) -> String

Note: This Question is unanswered, help us to find answer for this one

184.
What is the output of this segment of code?
var x = 0
for index in 1...5 {
++x
}
println("\(x)")

compile error

Answer

Correct Answer: 5

Note: This Question is unanswered, help us to find answer for this one

185.
Which of the following statements about Extensions is false?

Extensions can add new functionality to a type.

Keyword for Extensions is "extension"

Extensions can override existing functionality.

Extensions can make an existing type confirm to a protocol

Answer

Correct Answer: Extensions can override existing functionality.

Note: This Question is unanswered, help us to find answer for this one

186.
Which one is correct function definition?

funcsayHello(personName: String) -> String {}

funcsayHello(personName-> String) -> String {}

funcsayHello(personName-> String) : String {}

funcsayHello(personName: String) : String

Answer

Correct Answer: funcsayHello(personName: String) -> String {}

Note: This Question is unanswered, help us to find answer for this one

187.
If a class has a superclass and conforms to multiple protocols, what is the correct order to list their names in the initial definition of the Subclass?

Protocols first, super class followed by comma.

Protocols and super class can be listed in any order.

Super class first, protocols followed by comma.

Answer

Correct Answer: Super class first, protocols followed by comma.

Note: This Question is unanswered, help us to find answer for this one

188.
Which of these operators is used to check whether or not two instances are identical?

equalsTo

===

identicalTo

Answer

Correct Answer: ==

Note: This Question is unanswered, help us to find answer for this one

189.
Which of the following could be used to loop through the range of numbers 5-12 including 12?

for i in 512

for i in 5,i>12,i++

for i in 5..<12

for i in 4..<12

Answer

Correct Answer: for i in 5,i>12,i++

Note: This Question is unanswered, help us to find answer for this one

190.
With which keyword can you declare a constant in Swift?

let

const

final

define

Answer

Correct Answer: let

Note: This Question is unanswered, help us to find answer for this one

191.
To declare a function in Swift you would use what keyword?

function

new func

var

let

func

Answer

Correct Answer: func

Note: This Question is unanswered, help us to find answer for this one

192.

In the below text, what is the property name?

class Square: NamedShape {

var sideLength: Double

 func area() -> Double {
    return sideLength * sideLength
}

}

sideLength

Square

NamedShape

area

Answer

Correct Answer: sideLength

Note: This Question is unanswered, help us to find answer for this one

193.

In the below text, what is the super class name?

class Square: NamedShape {

var sideLength: Double

func area() -> Double {
     return sideLength * sideLength
}

}

Square

Double

area

sideLength

NamedShape

Answer

Correct Answer: NamedShape

Note: This Question is unanswered, help us to find answer for this one

194.
What is the correct way to compare the equality of two String type objects in Swift?

equalsTo

isEqual

Answer

Correct Answer: ==

Note: This Question is unanswered, help us to find answer for this one

195.
Which is not a control transfer statement in Swift?

goto

break

fallthrough

return

continue

Answer

Correct Answer: goto

Note: This Question is unanswered, help us to find answer for this one

196.
Which keyword do you use to define a class?

struct

class

interface

protocol

union

Answer

Correct Answer: class

Note: This Question is unanswered, help us to find answer for this one

197.
What is a mutating instance method in Swift?

When there is "mutating" keyword in front of extension.

When extension can add new types to existing classes.

When instance method without extension can modify itself.

A method that modifies self

Answer

Correct Answer: When instance method without extension can modify itself.

Note: This Question is unanswered, help us to find answer for this one

198.

If we have a class named MyClass with a nested enum called Status, declared like so:

class MyClass {
    enum Status {
        case On, Off
    }
}

How would one indicate that a variable is an enum of type Status outside the context of MyClass?

var status: MyClass.Status = .On

var status: Status = .On

var status: MyClass<Status> = .On

var status: MyClass(Status) = .On

Answer

Correct Answer: var status: MyClass.Status = .On

Note: This Question is unanswered, help us to find answer for this one

199.
To declare a constant in Swift you would use:

let

var

func

override func

const

Answer

Correct Answer: let

Note: This Question is unanswered, help us to find answer for this one

200.
Can Structures be type cast in Swift?

Yes

Only those deriving from NSObject

Only when they conform to protocol TypeCast

Answer

Correct Answer: No

Note: This Question is unanswered, help us to find answer for this one

201.
What is the output of this segment of code:
var x = 0 for index in 1...5 { ++x } print("(x)")

None of this

Answer

Correct Answer: 5

Note: This Question is unanswered, help us to find answer for this one

202.
Swift can compile alongside what other language?

Objective C

Objective-C

Scala

Erlang

Answer

Correct Answer: Objective C

Note: This Question is unanswered, help us to find answer for this one

203.
Which Swift Type is used to group multiple values into a single compound value? For example:let compoundValue = (3, 5)

GroupObject

Tuple

Ordered

Struct

Answer

Correct Answer: Tuple

Note: This Question is unanswered, help us to find answer for this one

204.
What symbol is used like a tuple to access arguments in Abbreviated Swift Closure syntax?

Answer

Correct Answer: $

Note: This Question is unanswered, help us to find answer for this one

205.
What is the type of Swift Enumerations?

Reference type

Class type

Collection type

Value type

Answer

Correct Answer: Value type

Note: This Question is unanswered, help us to find answer for this one

206.
What is the most basic difference between Value and Reference types?

Copying Value type creates an shared instance where Reference type creates independent instance

Value type instance share a single copy of the data where Reference type instances keeps a unique copy of its data

Assigning a Value type to a new variable copies its contents to a new instance, where Reference types do not.

Answer

Correct Answer: Assigning a Value type to a new variable copies its contents to a new instance, where Reference types do not.

Note: This Question is unanswered, help us to find answer for this one

207.
What happens when Swifts String, Array, and Dictionary objects are assigned to a new constant or variable?

They are copied.

They are always assigned and passed around as a reference to an existing instance.

They are assigned or copied according to the variable definition.

Answer

Correct Answer: They are copied.

Note: This Question is unanswered, help us to find answer for this one

208.
Which of these collection types is not included by default in standard Swift?

Set

Array

Dictionary

Answer

Correct Answer: NA

Note: This Question is unanswered, help us to find answer for this one

209.
Which of these statements declares cityArray as a mutable array?

let cityArray = ["Portland","San Francisco","Cupertino"]

let cityArray = [String]()

var cityArray = ["Portland","San Francisco","Cupertino"]

var cityArray = ["OR" : "Portland", "CA" : "San Francisco"]

Answer

Correct Answer: var cityArray = ["Portland","San Francisco","Cupertino"]

Note: This Question is unanswered, help us to find answer for this one

210.
Which keyword do you use to define a protocol?

protocol

interface

struct

class

Answer

Correct Answer: protocol

Note: This Question is unanswered, help us to find answer for this one

211.
How could we extend String to conform to protocol MyProtocol? Answers:

extension String(MyProtocol) { }

extension String, prot MyProtocol { }

extension String: MyProtocol { }

extension String, MyProtocol { }

Answer

Correct Answer: extension String: MyProtocol { }

Note: This Question is unanswered, help us to find answer for this one

212.
Which of the following statements is true when talking about classes and structures in Swift?

Both incorporate Inheritance

Both use reference counting

Both can be extended

Both are value types

Answer

Correct Answer: Both can be extended

Note: This Question is unanswered, help us to find answer for this one

213.
Which keyword is used to declare an extension in Swift?

extend

extension

typealias

mutating

subscript

Answer

Correct Answer: extension

Note: This Question is unanswered, help us to find answer for this one

214.
Which is correct for the following codes?

class Country{ let name: String init(name: String){ self.name = name; } var city: City? } class City{ let name: String init(name: String){ self.name = name; } var country: Country? } var bangladesh: Country? var khulna: City? bangladesh = Country( name: "Bangladesh" ) khulna = City( name: "Khulna" ) bangladesh?.city = khulna khulna?.country = bangladesh bangladesh = nil khulna = nil

Neither Country, nor City will be deallocated.

Both Country and City instance will be deallocated.

Only Country instance will be deallocated.

Only City instance will be deallocated.

Answer

Correct Answer: Neither Country, nor City will be deallocated.

Note: This Question is unanswered, help us to find answer for this one

215.
How can you use a nested type outside of its definition?

Prefix its name with the name of the type it is nested within.

It’s impossible, nested types can’t be used outside of definition.

It can be used from anywhere in the same block.

Use generic type for definition.

Answer

Correct Answer: Prefix its name with the name of the type it is nested within.

Note: This Question is unanswered, help us to find answer for this one

216.
How could we declare a custom protocol that inherits from Equatable?

protocol CustomEquatable: Equatable {…}

protocol CustomEquatable, Equatable {…}

protocol CustomEquatable extends Equatable {…}

protocol CustomEquatable<Equatable> {…}

Answer

Correct Answer: protocol CustomEquatable: Equatable {…}

Note: This Question is unanswered, help us to find answer for this one

217.
Why are IBOutlets declared with a weak attribute by default?

IBOutlets are not declared with a weak attribute by default.

To save memory

To increase loading speed

They are already retained by the view

Answer

Correct Answer: IBOutlets are not declared with a weak attribute by default.

Note: This Question is unanswered, help us to find answer for this one

218.
To which of these types does ARC apply?

Class

Structure

Enumeration

Basic types (String, Int, Bool)

Answer

Correct Answer: Class

Note: This Question is unanswered, help us to find answer for this one

219.
What is true about Memory management in Swift?

Swift uses Non-ARC so we need to handle the references manually.

Swift uses ARC but we still need to avoid reference cycles using weak and strong references etc.

Swift uses ARC so we don’t need to care about memory management at all.

Answer

Correct Answer: Swift uses ARC but we still need to avoid reference cycles using weak and strong references etc.

Note: This Question is unanswered, help us to find answer for this one

220.
How will ARC handle "Country" instance and "country2" reference when "country1" is set to "nil"?

class Country{ let name: String init(name: String){ self.name = name } } var country1: Country? var country2: Country? country1 = Country(name: "Bangladesh") country2 = country1

ARC will deallocate the Country instance but country2 will hold name it’s "Bangladesh"

ARC will not deallocate the Country instance but country2 will become "nil"

ARC will not deallocate the Country instance and country2 will hold it’s name "Bangladesh"

ARC will deallocate the Country instance and country2 will become "nil"

Answer

Correct Answer: ARC will not deallocate the Country instance and country2 will hold it’s name "Bangladesh"

Note: This Question is unanswered, help us to find answer for this one

221.
What will be the final value of "a.data" and "b.data" after following codes are executed?

struct A { var data: Int = 2 } var a = A() var b = a var c = b c.data = 10 a.data = 5

a.data = 10 and b.data = 2

a.data = 2 and b.data = 5

a.data = 5 and b.data = 5

a.data = 5 and b.data = 2

Answer

Correct Answer: a.data = 5 and b.data = 2

Note: This Question is unanswered, help us to find answer for this one

222.
What is the type of Swift String, Dictionary, Array?

Class

Union

Enum

Structure

Answer

Correct Answer: Class

Note: This Question is unanswered, help us to find answer for this one

223.
Which keyword do you use to define a function?

func

function

procedure

let

extension

Answer

Correct Answer: func

Note: This Question is unanswered, help us to find answer for this one

224.
What is the name of the following function: func potteryBarn (name: String, score: Int) -> String { return "Hello (name)! Your score is (score)." }

String

name: String, score: Int

potteryBarn

func

Answer

Correct Answer: potteryBarn

Note: This Question is unanswered, help us to find answer for this one

225.
AnyObject can represent:

an instance of any class type.

function types.

an instance of any type at all.

Answer

Correct Answer: an instance of any class type.

Note: This Question is unanswered, help us to find answer for this one

226.
Which of these is an invalid constant or variable declaration?

let = 3.14159

let <pi> = 3.14159

let = ""

let = "dogcow"

Answer

Correct Answer: let = 3.14159

Note: This Question is unanswered, help us to find answer for this one

227.
To loop through a range of the numbers 1-9 without using 9, you would write…

for i in 0…8

for i in 0>..9

for i in 1<..8

for i in 1..<9

Answer

Correct Answer: for i in 1..<9

Note: This Question is unanswered, help us to find answer for this one

228.
Which is the correct optional form of a down cast operator?

as?

as!

as.

as>>

Answer

Correct Answer: as?

Note: This Question is unanswered, help us to find answer for this one

229.
What are the names of the input parameters in the following function: func potteryBarn (name: String, score: Int) -> String {return "Hello (name)! Your score is (score)."}

String, Int

potteryBarn

name, score

Answer

Correct Answer: name, score

Note: This Question is unanswered, help us to find answer for this one

230.
What is the return type in the following declaration: func potteryBarn (name: String, score: Int) -> String { return "Hello (name)! Your score is (score)." }

Integer

String

Function

Constant

Answer

Correct Answer: String

Note: This Question is unanswered, help us to find answer for this one

231.
What is the result of the following code? func potteryBarn (name: String, score: Int) -> String { return "Hello (name)! Your score is (score)." } potteryBarn ("Tom" , 2)

Hello Tom! Your score is 2.

name: Tom, score: 2

Hello Tom!

potteryBarn = "Hello Tom! Your score is 2."

Answer

Correct Answer: Hello Tom! Your score is 2.

Note: This Question is unanswered, help us to find answer for this one

232.
When declaring a function, what symbol is used to indicate that an internal parameter name should also be used as an external parameter?

_ (right answer)

Answer

Correct Answer: _ (right answer)

Note: This Question is unanswered, help us to find answer for this one

233.
In what order will the following statements appear in the console? println("1") dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY _DEFAULT, 0), {println("2")}); println("3")

1/3/2

3/1/2

1/2/3

2, 1,2

Answer

Correct Answer: 1/3/2

Note: This Question is unanswered, help us to find answer for this one

234.
In what queue should all UI code be handled?

BackgroundQueue

UIQueue

Any Queue

MainQueue

Answer

Correct Answer: MainQueue

Note: This Question is unanswered, help us to find answer for this one

235.
Which of the following is correct to cube Integer?

extension Int { mutating func cube () { self = selfselfself } }

extension Int { mutating func cube () { return selfselfself } }

extension Int { func cube () { self = selfselfself } }

extension Int { func cube () { return selfselfself } }

Answer

Correct Answer: extension Int { mutating func cube () { self = selfselfself } }

Note: This Question is unanswered, help us to find answer for this one

236.
What will happen if you assign a value to a property within its own didSet observer?

didSet will be called again

It will create an infinite loop

The property will take on that value

Code will not compile

Answer

Correct Answer: The property will take on that value

Note: This Question is unanswered, help us to find answer for this one

237.
Which of following expressions can be used to rewrite the following UITableView instantiation in Swift UITableView *myTableView = [[UITableView alloc] initWithFrame: CGRectZero style: UITableViewStyleGrouped];

let myTableView: UITableView = new UITableView(frame: CGRectZero, style: .Grouped);

let myTableView: UITableView = UITableView.alloc().init(frame: CGRectZero, style: .Grouped);

let myTableView: UITableView = UITableView(frame: CGRectZero, style: .Grouped);

let myTableView: UITableView = UITableView(frame: CGRectZero, style: UITableViewStyleGrouped)

Answer

Correct Answer: let myTableView: UITableView = UITableView(frame: CGRectZero, style: .Grouped);

Note: This Question is unanswered, help us to find answer for this one

238.
What aspect of iOS development requires the use of NSOperation and/or Grand Central Dispatch (GCD)?

Multithreading

serial task

None

Message Sending

Answer

Correct Answer: Multithreading

Note: This Question is unanswered, help us to find answer for this one

239.
In the below text, what is the name of the class’s only method? Class Square: NamedShape { var sideLength: Double func area() -> Double { return sideLength*sideLength } }

sideLength

area

Square

NamedShape

Double

Answer

Correct Answer: area

Note: This Question is unanswered, help us to find answer for this one

240.
In the below text, what is the class name? Class Square: NamedShape { var sideLength: Double func area() -> Double { return sideLength*sideLength } }

NamedShape

Square

class

Double

sideLength

Answer

Correct Answer: Square

Note: This Question is unanswered, help us to find answer for this one

241.
In the below text, what type of return does the function ‘area’ give? Class Square: NamedShape { var sideLength: Double func area() -> Double { return sideLength*sideLength } }

Int

the area of a square

Double

area

Answer

Correct Answer: Double

Note: This Question is unanswered, help us to find answer for this one

242.
Which of following statements about functions is wrong?

In-out parameters might have a default value

Function might have multiple return values

Function might not have return values

Function names might be the same with another but at least one parameter should be different

Answer

Correct Answer: In-out parameters might have a default value

Note: This Question is unanswered, help us to find answer for this one

243.
What specifies custom infix operator?

it is a binary operator, taking a left and right hand argument

it is a unary operator written before its operand

it is a unary operator written after its operand

it is a reserved word that must be preceded with **

Answer

Correct Answer: it is a binary operator, taking a left and right hand argument

Note: This Question is unanswered, help us to find answer for this one

244.
What are the available arithmetic overflow operators in Swift?

op+,op-,op*,op/,op%

&+,&-,&*,&/,&%

+,-,*,/,%

&, |, &&, ||

Answer

Correct Answer: &+,&-,&*,&/,&%

Note: This Question is unanswered, help us to find answer for this one

245.
Which of the following statements is true regarding Swift closures and functions?

Functions and Closures are not related

A Function is a Closure declared within the scope of a Class

A Function is a named Closure

Closures can’t be used as arguments, Functions can

Answer

Correct Answer: A Function is a named Closure

Note: This Question is unanswered, help us to find answer for this one

246.
What is a trailing closure?

A closure expression that is called directly after another closure expression

A closure expression that is written outside of (and after) the parentheses of the function call it supports.

A closure expression that is declared within the scope of another closure expression.

A closure expression that is declared at the property of an object.

Answer

Correct Answer: A closure expression that is written outside of (and after) the parentheses of the function call it supports.

Note: This Question is unanswered, help us to find answer for this one

247.
How could the following closure be rewritten to use shorthand arguments? s2 } ) >

reversed = sorted(names, { $0 ,$1 in $0 > $1 } )

reversed = sorted(names, { $0 > $1 } )

reversed = sorted(names, { $0 ,$1 } )

reversed = sorted( { $0 > $1 } )

Answer

Correct Answer: reversed = sorted(names, { $0 > $1 } )

Note: This Question is unanswered, help us to find answer for this one

248.
How could you call the following function that takes a closure as an argument using trailing closure syntax: ()) { // function body goes here }>

funcWithClosure ({ //closure’s body goes here })

funk funcWithClosure ({ //closure’s body goes here })

funcWithClosure() { //closure’s body goes here }

funcWithClosure { //closure’s body goes here )

Answer

Correct Answer: funcWithClosure() { //closure’s body goes here }

Note: This Question is unanswered, help us to find answer for this one

249.
Let’s assume "numbers" is an array of unsorted integers. Which of these could be used to sort numbers?

numbers.sort({$0, $1 in $0 > $1})

numbers.sort({s1 > s2})

numbers.sort({$0 > $1})

numbers.sort(){s1 > s2}

Answer

Correct Answer: numbers.sort({$0 > $1})

Note: This Question is unanswered, help us to find answer for this one

250.
Choose the answer that declares an optional closure.

var closureName: (parameterTypes) -> (returnType)

typealias closureType = (parameterTypes) -> (returnType)

var closureName: ((parameterTypes) -> (returnType))

let closureName: closureType = { … }

Answer

Correct Answer: var closureName: ((parameterTypes) -> (returnType))

Note: This Question is unanswered, help us to find answer for this one

251.
How can we use optional binding to determine if the variable string is not nil?

if let str = string {…}

if string {…}

if string as String {…}

if let string {…}

Answer

Correct Answer: if let str = string {…}

Note: This Question is unanswered, help us to find answer for this one

252.
What set of keywords is most commonly used to iterate over a collections of items?

for each

switch case

do while

for in

Answer

Correct Answer: for in

Note: This Question is unanswered, help us to find answer for this one

253.
How could we cast the following array into an NSArray that accesses the NSArray method:
componentsJoinedByString() < let arr = ["1", "2", "3"]

arr.toNSArray.componentsJoinedByString(",")

NSArray(arr).componentsJoinedByString(",")

(arr as NSArray).componentsJoinedByString(",")

(arr bridge NSArray).componentsJoinedByString(",")

Answer

Correct Answer: (arr as NSArray).componentsJoinedByString(",")

Note: This Question is unanswered, help us to find answer for this one

254.
How could one declare a Swift Array type that can store any type of class object?

var arr: [id] = [ ]

var arr: [AnyObject] = [ ]

[AnyObject] arr = [ ]

var arr = NSArray<AnyObject>()

Answer

Correct Answer: var arr: [AnyObject] = [ ]

Note: This Question is unanswered, help us to find answer for this one

255.
Which is correct regarding optional form of the type cast operator (as?)?

It will trigger a runtime error if you try to downcast to an incorrect class type.

This is used when you are sure that the downcast will always succeed

Return value will be nil if the downcast was not possible

Answer

Correct Answer: Return value will be nil if the downcast was not possible

Note: This Question is unanswered, help us to find answer for this one

256.
How could we create a subclass of the Structure, CGRect?

struct MyRect: CGRect {}

struct CGRect(MyRect) {}

You can not subclass a Structure

struct MyRect extends CGRect {}

Answer

Correct Answer: You can not subclass a Structure

Note: This Question is unanswered, help us to find answer for this one

257.
Considering the following code, which statement is Correct:
let array1 = ["A", "B", "C"] var array2 = array1 array2.append("D")

array1 will be copied to array2 after the assignment

Reference count of array1 won't change after the assignment

array1 will change to [A, B, C, D] after appending D

Code will not compile, can not assign constant array1 to variable array2

Answer

Correct Answer: Reference count of array1 won't change after the assignment

Note: This Question is unanswered, help us to find answer for this one

258.
Swift Extensions are similar to categories in Objective-C except:

Swift extension might have a specific name

Swift extension doesn’t functionality to previously defined type.

Swift can override method from original type.

Swift extensions are not named.

Answer

Correct Answer: Swift extensions are not named.

Note: This Question is unanswered, help us to find answer for this one

259.
What is a muting instance method in Swift?

When there is "muting" keyword in front of extension.

When extension can add new types to existing classes.

When instance method without extension can modify itself.

A method that modifies self.

Answer

Correct Answer: When instance method without extension can modify itself.

Note: This Question is unanswered, help us to find answer for this one

260.
What is the type name that represents a character in Swift?

Character

Char

String

NSString

Answer

Correct Answer: Character

Note: This Question is unanswered, help us to find answer for this one

261.
What is the name of the Objective-C Bridging Header given a product module named Example?

Example-Bridging-Swift.h

Example-Swift.h

Example-Bridging-ObjectiveC.h

Example-Bridging-Header.h

Answer

Correct Answer: Example-Bridging-Header.h

Note: This Question is unanswered, help us to find answer for this one

262.
What is used in Swift to represent any kind of object?

AnyObject

Nothing

Answer

Correct Answer: AnyObject

Note: This Question is unanswered, help us to find answer for this one

263.
How do closures capture references to variables by default ?

By weak reference

By strong reference

By unowned reference

By copy

Answer

Correct Answer: By strong reference

Note: This Question is unanswered, help us to find answer for this one

264.
When declaring an enumeration, multiple member values can appear on a single line, separated by which punctuation mark?

Semi-colon

Colon

Comma

Slash

Point

Answer

Correct Answer: Comma

Note: This Question is unanswered, help us to find answer for this one

265.
Which keyword do you use to declare enumeration?

var

enum

struct

case

Answer

Correct Answer: enum

Note: This Question is unanswered, help us to find answer for this one

266.
Which of the following types can be used use as raw value types for an enumeration?

Bool

Array

Int, String, Float

Dictionary

Answer

Correct Answer: Int, String, Float

Note: This Question is unanswered, help us to find answer for this one

267.
Which is used for down casting?

as!

is?

as?

Answer

Correct Answer: as!
as?

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

268.
Which keyword is used in Swift when we want a property of a class to initialize when it is accessed for the first time?

let

var

const

lazy

Answer

Correct Answer: lazy

Note: This Question is unanswered, help us to find answer for this one

269.
Which of the following declares a mutable array in Swift?

var x = [Int]

let x = [Int]

var x = [Int]()

let x = [Int]()

Answer

Correct Answer: var x = [Int]()

Note: This Question is unanswered, help us to find answer for this one

270.
Can enumeration type have methods?

Enumerations can have methods associate with them.

Enumerations can have only member values.

Answer

Correct Answer: Enumerations can have methods associate with them.

Note: This Question is unanswered, help us to find answer for this one

271.
Given that we have defined myChar like so :
let myChar: Character = "b" Which code segment can be considered a complete Switch statement and will run without any error?

switch myChar { case "a","A": println("The letter A") case "b","B": println("The letter A") }

switch myChar { case "a": println("The letter A") }

switch myChar { case "a": case "A": println("The letter A") default: println("Not the letter A") }

switch myChar { case "a","A": println("The letter A") default: println("Not the letter A") }

Answer

Correct Answer: switch myChar { case "a","A": println("The letter A") default: println("Not the letter A") }

Note: This Question is unanswered, help us to find answer for this one

272.
What type of object are Swift Structures?

Reference Type

Memory Type

Abstract Type

Value Type

Answer

Correct Answer: Value Type

Note: This Question is unanswered, help us to find answer for this one

273.
Which is correct regarding Swift enumeration members when they are defined?

Members are assigned a default integer value.

Members are assigned a random default integer value.

Members are not assigned default integer values.

Answer

Correct Answer: Members are not assigned default integer values.

Note: This Question is unanswered, help us to find answer for this one

274.
What keyword is used to indicate a custom operator that will appear in between two targets, similar to the addition operator in this example?
var sum = 10 + 10

@inter

between

infix

@center

Answer

Correct Answer: infix

Note: This Question is unanswered, help us to find answer for this one

275.
What is used to import Objective-C files into Swift?

Objective-C classes are automatically imported.

Objective-C classes are imported in the Swift file using the class.

Objective-C classes are imported via a Bridging Header.

Objective-C classes import themselves by declare @SwiftImportable.

Answer

Correct Answer: Objective-C classes are imported via a Bridging Header.

Note: This Question is unanswered, help us to find answer for this one

276.
In context of a Swift subscript, which of the following is correct?

struct MyStruct { var myStr = [String]() subscript (index : Int) -> String{ get{ return myStr[index] } set{ myStr[index] = newValue } } }

struct MyStruct { var myStr = [String]() subscript (index : Int) -> Int{ get{ return myStr[index] } set(newValue){ myStr[index] = newValue } } }

struct MyStruct { var myStr = [String]() subscript (index : Int) -> String{ get(){ return myStr[index] } set(newValue){ myStr[index] = newValue } } }

struct MyStruct { var myStr = [String] subscript (index : Int) -> String{ get(){ return myStr[index] } set(newValue){ myStr[index] = newValue } } }

Answer

Correct Answer: struct MyStruct { var myStr = [String]() subscript (index : Int) -> String{ get{ return myStr[index] } set{ myStr[index] = newValue } } }

Note: This Question is unanswered, help us to find answer for this one

277.
Which of these could be an appropriate protocol declaration in Swift?

@objc protocol someProtocal { optional var first: Int { get } }

@objc protocol someProtocal { optional var first: Int { set } }

protocol someProtocal { optional var first: Int { get } }

protocol someProtocal { var first: Int { set } }

Answer

Correct Answer: @objc protocol someProtocal { optional var first: Int { get } }

Note: This Question is unanswered, help us to find answer for this one

278.
Which of the following statements could be used to determine if a given variable is of String type?

if String.hierarchy(unknownVariable) { }

if unknownVariable is String { }

if unkownVariable: String { }

if (String)unknownVariable { }

Answer

Correct Answer: if unknownVariable is String { }

Note: This Question is unanswered, help us to find answer for this one

279.
Which of these is a valid definition of a generic function that incorporates inout parameters in Swift?

func swap<T>(inout a: T, inout b: T) { let temp = a a = b b = temp }

func swap<U,T>(inout a: U, inout b: T) { let temp = a a = b b = temp }

func swap<U,T>( a: U, b: T) { let temp = a a = b b = temp }

func swap<T>( a: T, b: T) { let temp = a a = b b = temp }

Answer

Correct Answer: func swap<T>(inout a: T, inout b: T) { let temp = a a = b b = temp }

Note: This Question is unanswered, help us to find answer for this one

280.
Which keyword is used on a function inside an Enumeration to indicate that the function will modify 'self'?

modifier

mutating

mutable

mod

mut

Answer

Correct Answer: mutating

Note: This Question is unanswered, help us to find answer for this one

281.
All Swift classes must inherit from which root class?

Swift classes do not require a root class.

NSObject

@ObjC

Root

Answer

Correct Answer: Swift classes do not require a root class.

Note: This Question is unanswered, help us to find answer for this one

282.
Which of the following structures has both computed and stored properties?

struct Rect { var origin = CGPointZero var center: CGPoint { get { // } set { // } } }

struct Rect { var center: CGPoint { get { // } set { // } } }

struct Rect { let origin = CGPointZero }

struct Rect { var origin = CGPointZero var center: CGPointMake(0,0) }

Answer

Correct Answer: struct Rect { var origin = CGPointZero var center: CGPoint { get { // } set { // } } }

Note: This Question is unanswered, help us to find answer for this one

283.
Which is the wrong definition of a protocol in Swift?

protocol SomeProtocol { var first: Int{ get } }

protocol SomeProtocol { var first: Int{ set } }

protocol SomeProtocol { var first: Int { get set } }

protocol SomeProtocol { var first: Int { get set } var second: Int { get } }

Answer

Correct Answer: protocol SomeProtocol { var first: Int{ set } }

Note: This Question is unanswered, help us to find answer for this one

284.
Which of these is not a valid property declaration in Swift?

final let x = 0

final lazy let x = 0

final lazy var x = 0

final var x = 0

Answer

Correct Answer: final lazy let x = 0

Note: This Question is unanswered, help us to find answer for this one

285.
Which of these is an appropriate syntax for declaring a function that takes an argument of a generic type?

func genericFunction(argument: T<Generic>) { }

func genericFunction<T>(argument) { }

generic func genericFunction(argument: T) { }

func genericFunction<T>(argument: T) { }

Answer

Correct Answer: func genericFunction<T>(argument: T) { }

Note: This Question is unanswered, help us to find answer for this one

286.
What is the name of the deinitializer in a Class declaration?

deinit

dealloc

release

Answer

Correct Answer: deinit

Note: This Question is unanswered, help us to find answer for this one

287.
Which of these is an appropriate syntax for dispatching a heavy operation to a background thread?

dispatch_async(DISPATCH_QUEUE_PRIORITY_BACKGROUND), { self.heavyOperation() })

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIO RITY_BACKGROUND, 0), { self.heavyOperation() })

DISPATCH_QUEUE_PRIORITY_BACKGROUND({ self.heavyOperation() })

dispatch_async({ self.heavyOperation() })

Answer

Correct Answer: dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIO RITY_BACKGROUND, 0), { self.heavyOperation() })

Note: This Question is unanswered, help us to find answer for this one

288.
Which one creates a dictionary with a key type of Integer and value of String?

var dict:[Int: String] = ["one":1]

var dict: [Int: String] = [1:"one"]

var dict: [String: Int] = [1:"one"]

var dict = ["one":1]

Answer

Correct Answer: var dict: [Int: String] = [1:"one"]

Note: This Question is unanswered, help us to find answer for this one

289.
What is the name of the Swift language feature that Objective-C Blocks are translated into?

Lambda

Callback

Closure

Selector

Answer

Correct Answer: Closure

Note: This Question is unanswered, help us to find answer for this one

290.
Which of these is a valid syntax for iterating through the keys and values of a dictionary?
let dictionary = [keyOne : valueOne, keyTwo : valueTwo]

for (key, value) in dictionary { println("Key: (key) Value: (value)") }

for (key, value) in enumerate(dictionary) { println("Key: (key) Value: (value)") }

for (key, value) in (dictionary.keys, dictionary.values) { println("Key: (key) Value: (value)") }

for (key, value) in dictionary.enumerate() { println("Key: (key) Value: (value)") }

Answer

Correct Answer: for (key, value) in dictionary { println("Key: (key) Value: (value)") }
for (key, value) in dictionary.enumerate() { println("Key: (key) Value: (value)") }

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

291.
Which one of the below functions definitions is wrong considering Swift language?

func haveChar(#string: String, character: Character) -> (Bool)

func mean(numbers: Double...) -> Double

func minMax(array: [Int]) -> (min: Int, max: Int)?

func minMax(array: [Int]) -> (min: Int?, max: Int?)

Answer

Correct Answer: func haveChar(#string: String, character: Character) -> (Bool)

Note: This Question is unanswered, help us to find answer for this one

292.
What does a retainCount represent in ARC?

The current number of strong references to an object.

The current number of instances of an object.

The total number of objects currently being retained in memory.

The total number of times an object has been allocated.

Answer

Correct Answer: The current number of strong references to an object.

Note: This Question is unanswered, help us to find answer for this one

293.
What is the name of the Xcode generated header file used to import Swift classes into an Objective-C Class given a product module named Example?

ExampleSwift.h

Example.Swift.h

Example+Swift.h

Example-Swift.h

Answer

Correct Answer: Example-Swift.h

Note: This Question is unanswered, help us to find answer for this one

294. In Apple Swift, which of the following operators cannot be overloaded?

Assignment operator (=)

Ternary conditional operator (?:)

Right bit shift and assign (>>=)

Add and assign (+=)

Answer

Correct Answer: Assignment operator (=)
Ternary conditional operator (?:)

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

295. In Apple Swift, which of the following options hold true?

8% 2 returns 0

16 % 5 returns 1.0

23 % 7.5 returns 0.5

-9 96 4 returns 1

Answer

Correct Answer: 8% 2 returns 0
23 % 7.5 returns 0.5

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

296. In Apple Swift, which of the following statements are correct regarding protocols?

They can be used as a return type in a function.

They cannot support multiple inheritance.

They cannot be used as the type of a property.

They can be used as the type of items in a dictionary.

Answer

Correct Answer: They can be used as a return type in a function.
They can be used as the type of items in a dictionary.

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

297. Which of the following statements are correct about properties in the Apple Swift language?

In the Apple Swift language. information about a property is def‌ined in multiple locations.

An Apple Swift property does not have a corresponding instance variable.

Computed properties can be def‌ined by enumerations in the Apple Swift language.

None of the above.

Answer

Correct Answer: An Apple Swift property does not have a corresponding instance variable.
Computed properties can be def‌ined by enumerations in the Apple Swift language.

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

298. ln Apple Swift. which of the following operators are right-associative?

&’

Answer

Correct Answer: ?:
??

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

299. In Apple Swift, which of the following variables and constants are computed lazily?

Global constants

Local constants

Global variables

Local variables

Answer

Correct Answer: Global constants
Global variables

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

300. In Apple Swift, which of the following statements are incorrect regarding structures?

Initializers can be def‌ined by structures to set up their starting state.

Methods can be def‌ined by structures to provide functionality.

Type casting enables us to verify and interpret the type of a structure instance at runtime.

Reference counting permits more than one reference to a structure instance.

Answer

Correct Answer: Methods can be def‌ined by structures to provide functionality.
Reference counting permits more than one reference to a structure instance.

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

301. Which of the following statements are incorrect regarding a deinitializer in Apple Swift?

A deinitializer of a class is written with a 'deinit' keyword.

There can be at most two deinitializers per class.

A deinitializer always takes one parameter.

Superclass deinitializers are always called.

Answer

Correct Answer: There can be at most two deinitializers per class.
A deinitializer always takes one parameter.

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

302. In Apple Swift, which of the following statements are correct about extensions?

They can def‌ine type methods.

They can override an existing functionality.

They can define new nested types, but not subscripts.

They can add computed properties.

Answer

Correct Answer: They can def‌ine type methods.
They can add computed properties.

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

303. In Apple Swift, if an optional variable is defined without providing an initial value, then that particular variable is automatically set to which of the following?

zero(0)

nil

NULL

Answer

Correct Answer: nil

Note: This Question is unanswered, help us to find answer for this one

304. Which of the following access levels is NOT provided by Apple Swift?

Public access

Private access

Protected access

Internal access

Answer

Correct Answer: Protected access

Note: This Question is unanswered, help us to find answer for this one

305. In Apple Swift, subscripts can take:

only one parameter.

only two parameters.

only three parameters.

any number of parameters.

Answer

Correct Answer: any number of parameters.

Note: This Question is unanswered, help us to find answer for this one

306.
Based on your analysis of the above code. find out the output generated by the following lines.
let b1 = abc([9,-7,3,110,4,721)
print("number: \(b1.x), \(b1.y)")

number: 27, 216

number: 216, 27

number: -21, 330

number: 330, -21

Answer

Correct Answer:

number: -21, 330

Note: This Question is unanswered, help us to find answer for this one

307. In Swift, which of the following collection types is/are implemented as (a) generic collection(s)? 0 Array

Dictionary

Lists

Both a and b

Both b and c

Both a and c

Answer

Correct Answer: Both a and b

Note: This Question is unanswered, help us to find answer for this one

308.
What will be the output of the following code?
class a1 {
func cn10
{
for var a = 9; a >=1; --a {
for var b = 9; b >= 0; --b{
if b%2==a/2 [
print((b%4),terminator: "“)
}
}
print("")
}}}
lets = a1()
s.cn1()

1 1 2 01

1 1 2 O 1

2 01 2 0

1 11 11

1 1 1 1 1

O 0 0 0 0

13131

02020

Answer

Correct Answer:

13131

02020

Note: This Question is unanswered, help us to find answer for this one

309.
What will be the output of the given Apple Swift code?
var nm = 5.0
class abc[
var x = 0.0
var y: String [
return "\(nm)"
]
func kp0[
println("\(n m)")
1}
let s=abc()
println(s.kp0)
class sd1: abc[
var hB = false
func k1(){
let i = abc();
println("\(i.y)")
let be = sd1()
bc.hB = true
println("\(bc.y)")
println(i.kp())
]}
class Tn: abc[
var nm=15.0
override func kp0[
println(15.0)
]}
let tr = Tn0
tr.kp0

5.0

15.0

5.0

15.0

Answer

Correct Answer:

5.0

15.0

Note: This Question is unanswered, help us to find answer for this one

310. In Apple Swift, a class:

must have at least one designated initializer.

must have at least two designated initializers.

must have at least three designated initializers.

cannot have a designated initializer.

Answer

Correct Answer: must have at least one designated initializer.

Note: This Question is unanswered, help us to find answer for this one

311. In Apple Swift, which of the following symbols is used to write an implicitly unwrapped optional?

Answer

Correct Answer: !

Note: This Question is unanswered, help us to find answer for this one

312. ln Apple Swift, which of the following references should be used when it is known that the reference will never be nil during its lifetime?

Weak references

Unowned references

None of the above references can be used

Answer

Correct Answer: Unowned references

Note: This Question is unanswered, help us to find answer for this one

313.
What will be the output of the following Apple Swift code?
enum Abc [
case Mark
case John
case Andrew
case Lucy
case June
case Kate
]
enum Class [
case First. Second. Third. Fourth. Fifth. Sixth. Seventh
1
var n1 = Abc.Lucy
n1 = .John
print(n1)
let sp = Class.Sixth
sp = .Third
switch sp {
case .Third:
print("Perrnitted to the cricket ground")
default:
print("Not Permitted to the cricket ground")
]

John

Not Permitted to the cricket ground

(Enum Value)

Not Permitted to the cricket ground

John

Permitted to the cricket ground

Code will give compilation error.

Answer

Correct Answer:

Code will give compilation error.

Note: This Question is unanswered, help us to find answer for this one

314. In Apple Swift, if we dont want to provide an external name for the second parameter of a method, then which of the following symbols can be used to override the default behavior?

#: (Hash)

_ (Underscore)

& (Ampersand)

$ (Dollar)

Answer

Correct Answer: _ (Underscore)

Note: This Question is unanswered, help us to find answer for this one

315.
Based on your analysis of the following Apple Swift code, identify from the given options the code that will generate compilation error when executed.
func abc(inout a: T, inout _ b: T) {
let a1 = a
a = b
b = a1
print("\(a) \(b)")
}

var z =

var p = 5.0

var q = 22/50

abc(&p, &q)

var r = 2.15

var s =19.0/31

abc(&r. 8:5)

Both options a and b

Both options a and c

Answer

Correct Answer:

var z =

Note: This Question is unanswered, help us to find answer for this one

316.
Analyze the following Apple Swift code and select its correct output from the given options.
struct a1 [
var x = 0.0, y = 0.0
}
struct b1 {
var w = 0.0. h = 0.0
}
struct Rt{
var n1 = a1()
var 51 = b1()
var c1: a1 {
getl
let cX = n1.x + (sI.w / 2)
let CY = n1.y -|- (s1.h / 2)
return a1(x: cX. y: cY)
}
set(cc) [
n1.x = cc.x - (s1.w ‘36 4)+2.5
n1.y = my - (sl.h % 4)+2.5
I I I
var rr = Rt(n1: a1(x: 0.0, y: 0.0),
$1: b1(w: 10.0, h: 10.0))
let isc = rr.c1
rr.c1 = a1(x: 16.0, y: 16.0)
print("\(rr.n1.x), \(rr.n1.y)")

10,0,10.0

12.5. 12.5

16.5.16.5

18.5.18.5

Answer

Correct Answer:

16.5.16.5

Note: This Question is unanswered, help us to find answer for this one

317.
What will be the output of the last line of the given Apple Swift code?
let a=4
print(a&+0)
print(a&-O)
print(a&0)
print(a<<1)
print(a>>1)
print(a<<2)

Answer

Correct Answer:

Note: This Question is unanswered, help us to find answer for this one

318.
Analyze the Apple Swift code given in Image 1, and choose its correct output from Image

(i)

(ii)

(iii)

Answer

Correct Answer: (i)
(ii)

Note: This question has more than 1 correct answers

Note: This Question is unanswered, help us to find answer for this one

319.
Which of the following statements are valid regarding an assignment operator in Apple Swift?
1. let b=10
2. let (a,b) = (2, 3)
3. if a = b { )

Only1 and 2

Only 2 and 3

Only1 and 3

All the three statements are valid

Answer

Correct Answer:

Only1 and 2

Note: This Question is unanswered, help us to find answer for this one

320. In Apple Swift, which type of parameters cannot be used by subscripts?

Variable parameters

In-out parameters

Variadic parameters

Answer

Correct Answer: In-out parameters

Note: This Question is unanswered, help us to find answer for this one

321.
What will be the output of the following code?
class 81 (
func cn10
l
for var a = 9; a >= 1; --a[
for var b = 9; b >= 0; --b[
if b%2==a/2 [
print((b%4).terminator: "")
I
I
print("")
III
let s = a10
s.cn10

311201

11201

20120

1111

00000

13131

02020

Answer

Correct Answer:

13131

02020

Note: This Question is unanswered, help us to find answer for this one

322.
Choose True or False.
In Apple Swift, structures are reference types, whereas classes are value types.

True

False

Answer

Correct Answer:

False

Note: This Question is unanswered, help us to find answer for this one

323.
How many times will the following Apple Swift code print the word "green"?
for p in 21...34[
if p%2==1[
var a = "red"
var b: String?
var c = b ?? a
print( c)
}
else if p%3==2{
let a = "green"
let e = "red"
var f = e ?? a
print(f)
}
else(
var g = "green"
var h: String?
var k = h ?? g
print(k)
}
}

Answer

Correct Answer:

Note: This Question is unanswered, help us to find answer for this one

324.
What will be the output of the following code?
func abc(p: Double...) -> Double {
var sm: Double = O
for number in p[
sm += number
I
return sm I Double{p.count)
I
print(abc(6, 7.25, 16.75))

9.0

9.7

10.0

Code will generate compilation/runtime error.

Answer

Correct Answer:

10.0

Note: This Question is unanswered, help us to find answer for this one

325.
What will be the output of the following Apple Swift code?
func abc(param1: String) -> lnt[
print(param1)
return param1.characters.count
}
func xyz(param1: String) [
abc(paramI)
}
xyz.("John Smith")

John Smith

John Smith10

10John Smith

Answer

Correct Answer:

Note: This Question is unanswered, help us to find answer for this one

326. In Apple Swift, which of the following is the correct "identical to" operator?

===

Answer

Correct Answer: ===

Note: This Question is unanswered, help us to find answer for this one

327. In Apple Swift, which of the following statements is incorrect regarding inheritance?

Property observers can be added to inherited properties of a class.

All the classes in Apple Swift are inherited from a universal base class.

Multiple inheritance for classes cannot be supported by Apple Swift.

Answer

Correct Answer: All the classes in Apple Swift are inherited from a universal base class.

Note: This Question is unanswered, help us to find answer for this one

328.
What will be the output of the given Apple Swift code?
let a;zUlnt8 = 0b11101111
let sz;lnt8 = 0b00110011
let c=a&b
print(c)

Answer

Correct Answer:

Note: This Question is unanswered, help us to find answer for this one

329.
In Apple Swift, which of the given statements is correct about initializers?
1. Failable and non-failable initializers can be def‌ined with the same name and parameter types
2. No value can be returned by initializers.
3. A failable initializer cannot delegate to a non-failable initializer.

Only1

Only 2

Only 3

Answer

Correct Answer:

Only 2

Note: This Question is unanswered, help us to find answer for this one

330. Which of the following options holds true for observers in Apple Swift, when a property is set in an initializer before delegation takes place?

Only willset observer is called.

Only didset observer is called.

Neither willset nor didset observer is called.

Answer

Correct Answer: Neither willset nor didset observer is called.

Note: This Question is unanswered, help us to find answer for this one

331.
In Apple Swift, which of the following parameters can be used in a closure expression?
1. Constant parameters
2. Variable parameters
3. Inout parameters
4. Variadic parameters
5. Tuple parameters

Only 1. 2. and 3

Only 1, 2, 3, and 5

Only 2, 3, and 5

Only 1. 2. 3. and 4

All of the given parameters can be used in a closure expression.

Answer

Correct Answer:

All of the given parameters can be used in a closure expression.

Note: This Question is unanswered, help us to find answer for this one

332.
Which of the following statements are incorrect regarding closures in Apple Swift?
1. In Apple Swift, a closure can capture all the references to variables from the surrounding context in which it is def‌ined, but cannot capture references to constants.
2. A nested function is a closure that has a name but it cannot capture any value from its enclosing function.
3. A global function is a closure that has a name and does not capture any value.

Only 2 and 3

Only1 and 3

Only1 and 2

Answer

Correct Answer:

Only1 and 2

Note: This Question is unanswered, help us to find answer for this one

Swift MCQs | Topic-wise

MCQ on Basic Swift

General Swift MCQs

Swift Subjects

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Basic Swift MCQ

1. How can you extract val to x in tuple vt? let vt = (name: "ABC", val: 5)

2. What is the type of vals in this code? let vals = ["a", 1, "Hi"]

3. What is the value of numbers in the code below? let numbers = [1,2,3,4,5,6].filter{ $0 % 2 == 0}

4. In the code below, AOM must be a(n)? class AmP : MMM, AOM { }

5. What enumeration feature allows them to store case-specific data? (Question does not make that much sense though. )

6. What is printed to the console when this code is executed? "t".forEach { (char) in; print(char) }

7. What is the value of val after this code is executed? let i = 5; let val = i * 6.0

8. What is true of this code? let name: String?

9. What does this code print? let names = ["Bear", "Tony", "Svante"] print(names[1]+"Bear")

10. How many times this code will be executed? —OR— How many times will this loop be performed? for i in ["0", "1"]{print(i)}

11. How do you declare an optional String?

12. When is deinit called?

13. DispatchQueue.main.async takes a block that will be

14. How can you sort this array?

15. What prints to the console when executing this code? let x = try? String.init("test") print(x)

16. What is wrong with this code? Let val = 5.0 + 10

17. What is wrong with this code? var x = 5; x = 10.0

18. What data type is this an example of? let vals = ("val", 1)

19. Which of these choices is associated with unit testing?

20. What is wrong with this code? for (key, value) in [1: "one", 2: "two"]{print(key, value)}

21. In the function below, what are this and toThat examples of? func add(this x: Int, toThat y: Int)->{}

22. How do you designated a failable initializer?

23. How would you call a function that throws errors and also returns a value?

24. What is the inferred type of x? let x = ["a", "b", "c"]

25. Which object allows you access to specify that a block of code runs in a background thread?

26. What must a convenience initializer call?

27. What is the base class in this code? class LSN : MMM {}

28. What is the value of test after this code executes? let vt = (name: "ABC", val: 5) let test = vt.0

29. What is the value of t after this code is executed? let names = ["Larry", "Sven", "Bear"] let t = names.enumerated().first().offset

30. What can AnyObject represent?

31. How many times will this loop be executed? for i in 0...100 {print(i)}

32. What is the correct way to add a value to this array? var strings = [1, 2, 3]

33. All value types in Swift are _ under the hood?

34. How do you reference class members from within a class?

35. Which code snippet correctly creates a typealias closure?

36. What is wrong with this code? if let s = String.init("some string") { print(s)}

37. How can you avoid a strong reference cycle in a closure?

38. How many values does vals have after this code is executed? var vals = Set = ["4", "5", "6"] vals.insert("5")

39. DidSet and willSet are examples of _?

40. What describes this line of code? let val = 5

41. When a function takes a closure as a parameter, when do you want to mark is as escaping?

42. What is the type of value1 in this code? let value1 = "\("test".count)"

43. The Codable protocol is _?

44. What is the correct way to call this function? func myFunc(_ a: Int, b: Int) -> Int {return a + b}

45. What is the type of this function? func add(a: Int, b: Int) -> Int { return a+b }

46. What is the value of y? var x: Int? let y = x ?? 5

47. What is the value of test in this code? var test = 1 == 1

48. What is the value of y? let x = ["1", "2"].dropFirst() let y = x[0]

49. Why is dispatchGroup used in certain situations?

50. What is the raw/underlying type of this enum? enum Direction {case north, south, east, west}

51. What is the error in this code? let x = 5; guard x == 5 { return }

52. What is this code an example of? let val = (Double)6

53. Typical range of type Int8 is __

54. The following are unordered collection types:

55. A sequence of characters surrounded by double quotes is called _____?

56. Can cyclical relationships exist in value types?

57. A closure is a function without a name.

58. var varB = 3.14159ng is the cvarB is inferred to be of type _____

59. print(myStr) What will be the output of the above code snippet in Swift4?

60. var myVar = 100myVar = "Hello World"print(varA)The output will be

61. We can create an array of any type

62. Which is the correct naming scheme for an Objective-C bridging header file into Swift project

63. Bridging header file will not be compiled due to the following issues:

64. Objective-C class factory methods will change into _____ after importing to Swift

65. Overriding functionality is possible using extension

66. New initializers can be provided using extension

67. What is the correct way to import an Objective-C class into bridging header file?

68. The following are collection types in SwiftNote: There may be more than one right answer.

69. var myName: Int = "John Doe"print(myName)The output will be

70. The 'let' keyword is considered as:Note: There may be more than one right answer.

71. How can you create a new name for an existing type in Swift?

72. In Swift, private properties of a class can be accessed in any of it's extension.

73. Can you pass Int to a String type variable?

74. Which of the following do you need to serialize and archive your custom types in Swift?

75. Stage when memory returned to stack or heap?

76. During which stage memory is taken from stack or heap?

77. What is the typical byte width of Float data type in Swift?

78. Weak references are declared as _____ types

79. unowned reference types are declared as __

58.
var varB = 3.14159ng is the c
varB is inferred to be of type _____

60.
var myVar = 100
myVar = "Hello World"
print(varA)
The output will be

68.
The following are collection types in Swift
Note: There may be more than one right answer.

69.
var myName: Int = "John Doe"
print(myName)
The output will be

70.
The 'let' keyword is considered as:
Note: There may be more than one right answer.

72.
In Swift, private properties of a class can be accessed in any of it's extension.

91.
Extension can be used to create a new nested type of the following:
Note: There may be more than one right answer.

93.
Which of the following are true about extension functionalities?
Note: There may be more than one right answer.

94.
extension Int {
subscript(var myInt: Int) -> Int {
var no1 = 1
while myInt > 0 {
no1 *= 10
--myInt
}
return (self / no1) % 10
}
}
print(12[0])
What is the output?

95.
After importing Objective-C code to Swift, the above method will be imported as
(instancetype)initWithFrame:(CGRect)frame
style:(UITableViewStyle)style;

101.
What is the correct way to import Objective-C files into Swift?

102.
What is the return type of the following code? func nameFunc() -> String { return "Jhon" }

103.
The following attribute can be used to allow a protocol to contain optional functions and to be used in ObjC?

104.
Suppose below variable declaration, select a right answer? import UIKit var str = "string" var ŝanĝiĝema = "хувьсагч" var & = "&"

105.
How can you fix the missing characters for the following code? func userScore -> Bool { return true }

106.
How to hide status bar in iOS app with Swift as follows?

107.
Which of the following is an appropriate syntax for dispatching a heavy operation to a background thread?

108.
If a class is named 'MyClass' with a nested enum called 'Status', how do you indicate that a variable is an enum of type 'Status' outside the context of 'MyClass'? class MyClass { enum Status { case On, Off } }

110.
Based on var index = UInt8.max, which of the following operation results to the value of zero for var index?

111.
Which of the following is the correct keyword for defining a constant in Swift?

112.
The following keyword in the context of a Switch statement is required to force the execution of a subsequent case?

113.
Which of the following statements is a valid way to extend the capabilities of our theoretical class, MyClass to conform to protocol MyProtocol?

114.
In Swift, objects are usually references to instances for both _____ and classes?

115.
What is the return value of the type check operator - is ?

116.
Which integer literals have a decimal value of 17? (choose all that apply)

117.
What is the correct way to declare Decomposed Tuple?

118.
How do you remove items from arrays? (choose all that apply)

119.
What are the Numeric Integer Literals? (choose all that apply)

120.
Which of the following is a correct answer for Enumerations?

121.
How to extract a string from URL data?

122.
Which of the following statements are true about Tuple?

123.
In Swift, what are the benefits of classes?

126.
What is the need for having structures?

127.
In Swift, what's the correct way variables consist?

128.
On which tag background color for the page can be set?

130.
Please check following code and tell what can be problem?

import UIKit ;

var intVar:Int?=3;

intVar = nil;

var strVar:String;

strVar = nil;

131.
Execute below code and tell what can be problem? import UIKit let fm = NSFileManager.defaultManager() fm.removeItemAtPath("file.old")

132.
Use the classes defined above to create a new Person instance, and try to access its numberOfRooms property as before?

133.
What does the following code?

import UIKit

var str1:String?="text1";

var str2:String="text2";

var int1:Int?=111;

var int2:Int=222;

var array:String[] = [str1, str2, int1, int2];

array=[];

134.
Extensions can add new instance ____?

136.
How to convert string into integer value? import UIKit let str_number = "320"

138.
Following code which is super class? class X: Y { let str:String let val:Int? … init() { … } deinit(){ … } }

139.
How to get local IP address in swift?

140.
Read the following code and select output?

import UIKit

var array:[String] = ["string1", "string2"];

print("array list has (array.count) items.");

142.
The structure of a value or ____ value?

143.
How to compare below 2 strings? let str1 = "string1" let str2 = "string2”

144.
Which of the following is safest for downcasting?

145.
If the following code executed what can be problem?

import UIKit

func MinMax(array: [Int]) -> (min: Int, max: Int)

{

var min = array[0];

var max = array[0];

for val in array[1..<array.count] {

if val< min { min = val }

else if val> max { max = val }

}

return (min, max)

}

146.
What will be the output of the following code snippet? let val1 = "Hello," let val2 = "World!" var result = val1 \ val2 print( result )

147.
A while loop performs a set of statements until a condition becomes false. These kinds of loops are best used when the number of iterations is not known before the first iteration begins. Swift provides two kinds of while loops?

148.
Closure expressions in Swift language follow crisp, optimization, and lightweight syntax styles which includes?

149.
In Swift there are ____ kinds of types named and Compound?