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Basic Objective C MCQ

1. What is wrong with this line of code? int temp = 1==1;

Temp is a keyword.

1==1 is invalid.

1==1 evaluates to a Boolean.

Nothing is wrong with it.

Answer

Correct Answer: Nothing is wrong with it.

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

2. You are worried about threaded access to a property and possible collision in writing. What directive should you use on the property?

Non-atomic

Strong

Weak

Atomic

Answer

Correct Answer: Atomic

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

3. What is significant about this function declaration? -(void)testFunc:(NSString**)str;

The parameter is passed by value and can not be changed

** is not allowed on a parameter

The parameter may be nil

The parameter is passed by reference and may be changed

Answer

Correct Answer: The parameter is passed by reference and may be changed

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4. Dot notation can be used for _?

Nothing, as they're never used in Objective-C

Function calls only

Property getter/setter

Parameter delimiters

Answer

Correct Answer: Property getter/setter

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5. What's the difference between an array and a set?

Arrays are ordered, non-unique values.

Arrays are stored sorted.

Sets are ordered, unique values.

Sets can contain nils.

Answer

Correct Answer: Arrays are ordered, non-unique values.

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6. What is this a declaration of? int(^foo)(int);

An Extension

A Generic

A block of code

An abstract class

Answer

Correct Answer: A block of code

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7. What are categories used for?

To extend other classes

To manage access control

To coordinate objects

To group classes

Answer

Correct Answer: To extend other classes

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8. If you want to store a small amount of information (e.g., user settings), whats the best, built-in way to go?

UserDefaults

Plist file

CoreData

TextFile

Answer

Correct Answer: UserDefaults

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

9. What is an enums base type for the code below? typedef enum { Foo1, Foo2} Foo;

There is no base type.

NSObject

Int

NSNumber

Answer

Correct Answer: There is no base type.

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10. Structs can have _?

Functions

Initializers

Fields

All of these answers

Answer

Correct Answer: Fields

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11. What is different about this function? +(void)doSomething;

It is static

It is abstract.

It is inline.

This code contains an error.

Answer

Correct Answer: It is static

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12. What best describes class inheritance in Objective-C?

Single inheritance but multiple protocol implementation

Objective-C doesn't support inheritance

Dual class inheritance

Unlimited class inheritance and protocol adherence

Answer

Correct Answer: Single inheritance but multiple protocol implementation

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

13. What does ARC stand for?

Automatic Reference Counting

Automatic Retain Checking

Async Retain Cycles

Automatic Release Code

Answer

Correct Answer: Automatic Reference Counting

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

14. What's wrong with this code?float x = 5.;

Nothing is wrong with this code.

Declarations do not need semicolons.

X=5 is an invalid float.

Variables can't be declared and initialized in the same state.

Answer

Correct Answer: Nothing is wrong with this code.

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15. What is foo? -(float)foo;

A function with a return type of float.

This code contains an error.

A variable declaration of type float.

A property of type float.

Answer

Correct Answer: A function with a return type of float.

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16. What is the key difference between NSDictionary and NSMutableDictionary?

NSMutableDictionary's values can change

NSMutableDictionary has not initializers.

NSDictionary can't be copied.

NSDictionary's values can change.

Answer

Correct Answer: NSMutableDictionary's values can change

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17. Property defaults include _?

Atomic/strong

Atomic/weak

Nonatomic/weak

Nonatomic/strong

Answer

Correct Answer: Atomic/strong

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18. For permanent storage of some data Apple provides:

Storage framework

Database framework

CoreData framework

None of the above

Answer

Correct Answer: CoreData framework

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19. To display some web page, Apple provides a predefined class called:

UIScrollView

UIWebView

UIButton

UIWebSiteView

Answer

Correct Answer: UIWebView

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20.
What will be printed on screen after running the following code?
int main()
{
int a = 5;
float c = .5f
printf("%.2f", a / c);
return 0;
}

Nothing: you will get a compile-time error

10.0

Answer

Correct Answer: Nothing: you will get a compile-time error

10.0

Note: This question has more than 1 correct answers

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

21. What’s the hierarchy of UITextView class until NSObject?

UITextView >> UITextField >> UIScrollView >> UIControl >> NSObject

UITextView >> UIResponder >> UIControl >> UIView >> NSObject

UITextView >> UIScrollView >> UIView >> UIResponder >> NSObject

UITextView >> UIScrollView >> UIConrol >> UIResponder >> NSObject

Answer

Correct Answer: UITextView >> UIScrollView >> UIView >> UIResponder >> NSObject

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

22. Which of the following is a valid property name of the NSException class?

“code”

“domain”

“userInfo”

“info”

Answer

Correct Answer: “userInfo”

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23. If you need to raise a new exception, you will use:

“@raise” statement

“@throw” statement

“@catch” statement

“@exception” statement

Answer

Correct Answer: “@throw” statement

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24. Which of these classes are collections?

NSArray, NSMutableArray, NSBinaryTree, NSMutableDictionary

NSSet, NSBinaryTree, NSRedTree, NSQueue, NSList

NSMutableArray, NSSet, NSTuple, NSDictionary

None of the above

Answer

Correct Answer: None of the above

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25. To create an animation, which starts slowly, but then accelerates as it progresses, you will use:

UIViewAnimationOptionCurveEaseInOut

UIViewAnimationOptionCurveLinear

UIViewAnimationOptionCurveOut

UIViewAnimationOptionCurveEaseIn

Answer

Correct Answer: UIViewAnimationOptionCurveEaseIn

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

26. Which of the following is a valid generics type definition?

NSMutableArray dogs = [NSMutableArray new];

NSMutableArray dogs;

NSMutableArray dogs = [NSMutableArray new]

Answer

Correct Answer: NSMutableArray dogs = [NSMutableArray new];

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27. Which of the following is a valid attribute for a property declared in protocol?

nonatomic

nullify

cascade

None of the above

Answer

Correct Answer: nonatomic

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28. Which of the following is true?

Calling “new” doesn’t claim an ownership of the object, you have to call “retain” after that at some point

Calling “init” increases the references count by +1

Calling “alloc” increases the references count by +1

None of the above

Answer

Correct Answer: Calling “alloc” increases the references count by +1

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

29. Which of the following is a valid property name of the NSError class?

“name”

“reason”

“domainName”

“domain”

Answer

Correct Answer: “domain”

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30. Which of the following is an animatable property of a CALayer object?

opacity

transformation

shadow

None of the above

Answer

Correct Answer: opacity

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31. A proper implementation of “dealloc” method in your custom class must include:

Releasing ownership on all of the owned properties and calling “[self dealloc];”

Releasing ownership on all of the owned properties and calling “[self release];”

Releasing ownership on all of the owned properties and calling “[super dealoc];”

Releasing ownership on all of the owned properties and calling “[super dealloc];”

Answer

Correct Answer: Releasing ownership on all of the owned properties and calling “[super dealloc];”

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32. Which statement contains a valid code for adding a method, which is not necessary to implement within a class which will conform to the protocol?

#required -(void)someMethod;

@optional -(NSString)someMethod

@required +(int)someMethod;

@optional -(NSString)someMethod;

Answer

Correct Answer: @optional -(NSString)someMethod;

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33. Which is a correct statement for declaring a new category for UIColor class?

@category UIColor (MyCategory)

@interface UIColor (MyCategory)

@extention UIColor: Mycategory

None of the above

Answer

Correct Answer: @interface UIColor (MyCategory)

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34. When deleting a CoreData NSManagedObject, you can specify to also delete its properties from the database, by setting a rule called:

“Nullify”

“Cascade”

“Deny”

None of the above

Answer

Correct Answer: “Cascade”

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35. Right after an exception occurs, your program executes the code from the:

“@handle” block

“@process” block

“@finally” block

“@catch” block

Answer

Correct Answer: “@catch” block

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36. Which statement about protocols is true?

There is no way to define a class function in protocol

When you are writing your own protocol, there is no way to inherit it from other(s)

Absolutely all functions are necessary to implement in a class which conforms to a given protocol

None of the above

Answer

Correct Answer: There is no way to define a class function in protocol

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37. Which of the following is NOT a predefined exception class name?

NSRangeException

NSInvalidArgumentException

NSGeneticException

NSPortSendException

Answer

Correct Answer: NSGeneticException

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38. If there was no “@catch” block specified for handling exceptions, what will happen then?

compile-time error

runtime error

the program will restore and continue execution normally

none of the above

Answer

Correct Answer: compile-time error

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39. Which is a correct statement to declare a new protocol?

@newProtocol ProtocolName

@protoclo ProtocolName

#protocol ProtocolName

None of the above

Answer

Correct Answer: None of the above

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40. What is the correct code to include C “Header.h” header in Objective-C “.m” source file?

There is no way to do this

#import “Header.h”

@import “Header.h”

include “Header.h”

Answer

Correct Answer: #import “Header.h”

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41. Which of the following is a correct name of memory management method?

Manual Reference Releases

Automatic Reference Counting

Autoinfered Retain Counting

None of the above

Answer

Correct Answer: Automatic Reference Counting

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42. Which of the following are valid property annotations?

nonatomic, strong, weak, nonnullable

copy, readonly, nullable, nonnullable

nullable, nonnul, atomic, weak

None of the above

Answer

Correct Answer: None of the above

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43. Which of the following is true?

“assign” property attribute stores a direct pointer without any “retain” / “release” calls

“copy” property attribute creates and assigns a copy of an object it is set to, but you will need to call a “release” on the original variable

“retain” property attribute stores a copy of an object with claiming ownership to both original object and it’s copy

None of the above

Answer

Correct Answer: “assign” property attribute stores a direct pointer without any “retain” / “release” calls

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44. If a is an integer, the expression !a (...)?

Uses the logical negation operator

Has the value 0 if a is non-zero

Has the value 1 if a is zero

All of the above

Answer

Correct Answer: All of the above

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45. As categories can't have instance variables, what class could you use to implement a full class only with categories

NSArray

NSMutableDictionary

NSSet

None of the above

1.0

None of the above

dealloc

Answer

Correct Answer: NSMutableDictionary
dealloc

Note: This question has more than 1 correct answers

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46.

Using object-oriented programming the object that sends a message

property

receiver

target

Answer

Correct Answer: id

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

47.
All of the methods in a (...) annotated with @required must be implemented.

protocol

48.
When an object's retainCount reaches 0, which message is automatically sent to that Object?

dealloc

alloc

automated

object

Answer

Correct Answer: dealloc

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

49.
Considering the following Objective-c snippet, which of the following is NOT correct ?
#import <Foundation/Foundation.h> @interface SampleClass:NSObject - (void)sampleMethod; @end @implementation SampleClass - (void)sampleMethod{ NSLog(@"Hello, World! \n"); } @end int main() { /* my first program in Objective-C / SampleClass sampleClass = [[SampleClass alloc]init]; [sampleClass sampleMethod]; return 0; }

The first line of the program `#import <Foundation/Foundation.h>` is a preprocessor command,

which tells a Objective-C compiler to include `Foundation.h` file before going to actual compilation.

`@interface SampleClass:NSObject` shows how to create an interface. It inherits NSObject, which is the base class of all objects.

`(void)sampleMethod;` shows how to declare a method.

`@end` marks the end of the class

`int main()` is the main function where program execution begins

Answer

Correct Answer: `@end` marks the end of the class

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50.
Considering the following Objective-C code, which of the following statements is correct ?
// function declaration intfunc(); int main() { // function call inti = func(); } // function definition intfunc() { return 0; }

Even though the function `func()` is not defined at the the time of the call, the code will run because the function has been previously declared.

The code won't run because the `func()` was not defined at the time of the call.

The code won't run because the initial function declaration is empty.

The code won't run because the `main()` function should be the first declaration in the code.

None of the above

Answer

Correct Answer: The code won't run because the `func()` was not defined at the time of the call.

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51.
Which of the following is a correct sample of block implementation in Objective-C?

`void (simpleBlock)(void) = {NSLog(@"This is a block");};`

`void (^simpleBlock)(void) = ^{NSLog(@"This is a block");};`

`void (~simpleBlock)(void) = ~{NSLog(@"This is a block");};`

`void ($simpleBlock)(void) = ${NSLog(@"This is a block");};`

Answer

Correct Answer: `void (^simpleBlock)(void) = ^{NSLog(@"This is a block");};`

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52.
It's possible to add a (...) to the standard NSString class, for example, to extend its functionality.

53.
Which of the following is NOT correct to state about Objective-C language ?

Adds Smalltalk-style messaging to the C programming language

It's one of the programming languages used by Apple for the OS X and iOS operating systems

It's a general-purpose, object-oriented programming language

It's an interpreted programming language designed for object orientation

Answer

Correct Answer: It's an interpreted programming language designed for object orientation

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54.
In Objective-C, if I call performSelector:withObject:afterDelay: – is the object retained ?

Yes

Answer

Correct Answer: No

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55.
Considering best practices of memory management in Objective-C, is it correct to say that the delegate is never retained ?

Yes

Answer

Correct Answer: Yes

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56.
#import <Foundation/Foundation.h>int main() { inti = 17; char c = 'c'; /* ascii value is 99 */ int sum; sum = i + c; NSLog(@"sum : %d\n", sum ); return 0; }
When the above code is compiled and executed, it produces the following result:

sum : 116

sum : Nil

this code will generate runtime error

None of the above

Answer

Correct Answer: sum : 116

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57.
The following Objective-C code defines
... @interface Fraction (MathOps) ... @end

a category called MathOps

a protocol called MathOps

None of the above

Answer

Correct Answer: a category called MathOps

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58.
In which of the following situations you would NOT use void types?

To define functions which do not return value

To define functions which do not accept any parameter

To assign a nullable value to variables

Answer

Correct Answer: To define functions which do not return value

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59.
Which of the following is NOT correct about Protocols ?

The methods under keyword @required must be implemented in the classes that conforms to the protocol

The syntax `<>` is used to specify a class conforming to protocol.

A single class cannot conform to multiple protocols.

The methods under @optional keyword are optional to implement.

Answer

Correct Answer: A single class cannot conform to multiple protocols.

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60.
The Objective-C code ... @interface MyClass : NSObject<Sample> ... @end

Indicates MyClass is part of the Sample category

Indicates MyClass conforms to the Sample category

Indicates MyClass conforms to the Sample protocol

Is not valid Objective-C syntax

Answer

Correct Answer: Indicates MyClass conforms to the Sample protocol

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61.
Considering the following Objective-C code, what will get printed:
#import <Foundation/Foundation.h>int main()
{ int sum = 17, count = 5; CGFloat mean; mean = (CGFloat) sum / count; NSLog(@"mean : %f", mean ); return 0; }

mean : 3

mean : 3.5

mean : 3.400000

mean : 4.0

Answer

Correct Answer: mean : 3.400000

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62.
Consider below declaration of Song object and tell proper way to call name property?
import @interface Song:NSObject { NSString name; NSString artist; } (NSString ) name; (NSString ) artist; @ end

mySong.name;

mySong->name;

[mySong name];

[mySong, name];

Answer

Correct Answer: mySong->name;
[mySong, name];

Note: This question has more than 1 correct answers

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63.
What is the best way to convert NSNumber into NSString?

intnum = [number intValue]; NSString *string = [NSStringstringWithFormat:@" %d", num];

NSString *string = [NSNumberstringValue];

NSString *string = [NSStringstringWithFormat:@" %f", (float) number];

Answer

Correct Answer: NSString *string = [NSNumberstringValue];

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64.
Name a property attribute that synthesizes accessors that are not thread safe?

automated

Interface Builder

nonatomic

deprecated

Answer

Correct Answer: nonatomic

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65.
Where does Objective C store objects, Heap or stack?

Heap or stack as the case of the objects

Stack

Heap

Answer

Correct Answer: Heap

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66.
Look at below code and tell correct output?
import static int count; intcnt; for (inti = 0; i<100; i++) { count++; cnt++; } NSLog(@"count=%d cnt=%d\n", count, cnt);

count=100 cnt=0

count=100 cnt=UNKNOWN

count= UNKNOWN cnt= UNKNOWN

count=100 cnt=100

Answer

Correct Answer: count=100 cnt=100

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67.
What is a local variable that has no default initial value and does not retain its value through method calls?

An auto variable

A static variable

A global variable

All of the above

Answer

Correct Answer: A static variable

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68.
Can you call C++ code from the Objective-C environment?

Yes, from any .mm file

Yes, from any .cpp file

Answer

Correct Answer: Yes, from any .mm file

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69.
Which of the following is a Singleton?

[NSFileManagerdefaultManager]

[NSFileManager* objects]

{NSFileManagerdefaultManager}

(NSFileManagerdefaultManager* objects)

Answer

Correct Answer: [NSFileManager* objects]

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70.
Look at below code and provide the reference counter value after it executes:
Object *anObj = [[Object alloc] init]; [anObj retain]; [anObj release]; [anObj release];

Reference counter will be 1

Reference counter will be 0, anObj will be deallocated automatically

Reference counter will be 1, anObj will be ready for the deallocation

Answer

Correct Answer: Reference counter will be 0, anObj will be deallocated automatically

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71.
What will be the output of following code?
BOOL isBool = YES; NSLog(@"%d", isBool);

Yes

Empty

Answer

Correct Answer: 1

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72.
Please pick the most suitable difference between alloc and dealloc?

alloc creates a new instance and dealloc removes the allocated instance alloc allocated instance memory area, and dealloc removes the allocated memory area

alloc creates a new instance and make the reference counter as 1, dealloc will remove the instance automatically when its reference counter become 0

alloc creates a new instance and make the reference counter as 1, dealloc will decrease reference

counter of the new instance

Answer

Correct Answer: alloc creates a new instance and make the reference counter as 1, dealloc will remove the instance automatically when its reference counter become 0

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73.
An object id with a value of 0?

nil

instance

Answer

Correct Answer: nil

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74.
How do you search an object in an object array?

NSEnumerator *enumerator = [array objectEnumerator]; while([enumerator nextObject]){…}

NSString *item = nil; For ( item in array){ … }

NSObject *item = nil; For ( item in array){ … }

Answer

Correct Answer: NSEnumerator *enumerator = [array objectEnumerator]; while([enumerator nextObject]){…}

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

75.
Property attribute that synthesizes only a getter for the property?

remote object

readonly

protocol

instance method

Answer

Correct Answer: readonly

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

76.
Which is the most proper answer to load plist file contents into an array?

NSArray * array = [[NSArrayalloc] initWithContentsOfFile:plistfile_path];

NSString * arraystring = [NSStringstringWithContentsOfFile: plistfile_path encoding:NSUTF8StringEncoding error:NULL]; NSArray *array = [arraystringconvertToArray];

NSMutableArray *array = [NSKeyedUnarchiverunarchiveObjectWithFile: plistfile_path];

Answer

Correct Answer: NSArray * array = [[NSArrayalloc] initWithContentsOfFile:plistfile_path];

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77.
Which of the following contain an INCORRECT way to declare and initialize an array ?

`double balance[5] = {1000.0, 2.0, 3.4, 17.0, 50.0};`

`double balance[] = {1000.0, 2.0, 3.4, 17.0, 50.0};`

`double balance = {1000.0, 2.0, 3.4, 17.0, 50.0}; `

`int n[ 5 ]; for ( i = 0; i < 5; i++ ){ n[ i ] = i + 1;}`

Answer

Correct Answer: `double balance = {1000.0, 2.0, 3.4, 17.0, 50.0}; `

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

78.
In Objective-C, sometime, you may find that you wish to extend an existing class by adding behavior that is useful only in certain situations. In order to add such extension to existing classes, Objective-C provides ...

categories and extensions

categories and expansions

sections and expansions

sections and extensions

Answer

Correct Answer: categories and extensions

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

79.
The (...) is an Objective-C directive, which is also used to define the aliases for various data types similar to (...). But (...) is limited to giving symbolic names to types only, whereas (...) can be used to define alias for values as well, like you can define 1 as ONE, etc.

#define, typedef, #define, typedef

#define, typedef, typedef, #define

typedef, #define, typedef, #define

typedef, #define, #define, typedef

Answer

Correct Answer: #define, typedef, typedef, #define

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

80.
Which of the following contain an INCORRECT concept regarding Objective-C programming ?

Fast enumeration is a language feature that allows you to enumerate over the contents of a collection.

A struct is a special C data type that encapsulates other pieces of data into a single cohesive unit. Like an object, but built into C.

Mutable types means you can change its contents later, but when you mark any object immutable, it means once they are initialized, their values cannot be changed. For example, NSArray, NSString values cannot be changed after initialized.

None of the above

Answer

Correct Answer: None of the above

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81.
Memory management is one of the most important processes in any programming language. It is the process by which the memory of objects are allocated when they are required and deallocated when they are no longer required. Objective-C Memory management techniques can be broadly classified into two types: "Manual Retain-Release" or MRR and "Automatic Reference Counting" or ARC. Which of the following is NOT correct regarding memory management in Objective-C ?

In MRR, we explicitly manage memory by keeping track of objects on our own.

In MRR, we own any object we create: We create an object using a method whose name begins with "alloc", "new", "copy", or "mutableCopy".

In MRR, when we no longer need an object, we must relinquish the ownership by sending it a release message; the autorelease message tough can only be sent in ARC contexts.

The fundamental difference between MRR and ARC is that the retain and release is handled by us manually in former while its automatically taken care of in the latter.

Answer

Correct Answer: In MRR, when we no longer need an object, we must relinquish the ownership by sending it a release message; the autorelease message tough can only be sent in ARC contexts.

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

82.
Memory management is one of the most important processes in any programming language. It is the process by which the memory of objects are allocated when they are required and deallocated when they are no longer required. In (...), when we no longer need it, we must relinquish ownership of an object we own: We relinquish ownership of an object by sending it a release message or an autorelease message. In Cocoa terminology, relinquishing ownership of an object is therefore typically referred to as "releasing" an object.

MRR

ARC

Gabage Collection

GCC

Answer

Correct Answer: ARC

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

83.
In Objective-C, retain counts are the way in which memory is managed. When you create an object, it has a retain count of (...). When you send an object a retain message, its retain count is incremented by (...). When you send an object a release message, its retain count is decremented by (...). When you send an object a autorelease message, its retain count is decremented by (...) at some stage in the future. If an objectʼs retain count is reduced to (...), it is deallocated.

1, 1, 1, 1, 0

0, 1, 1, 1, 0

1, 1, 1, 1, 1

0, 1, 1, 1, 1

Answer

Correct Answer: 1, 1, 1, 1, 0

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

84.
Objective-C allows you to define protocols, which declare the methods expected to be used for a particular situation. Protocols are implemented in the classes conforming to the protocol. The methods under keyword (...) must be implemented in the classes that conform to the protocol and the methods under (...) keyword are optional to implement.

@required, @optional

@optional, @required

@strong, @optional

@required, @weak

Answer

Correct Answer: @required, @optional

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

85.
In the real world, people on official business are often required to follow strict procedures when dealing with certain situations. In the world of object-oriented programming, it’s important to be able to define a set of behaviors that is expected of an object in a given situation. As an example, a table view expects to be able to communicate with a data source object in order to find out what it is required to display. This means that the data source must respond to a specific set of messages that the table view might send. The data source could be an instance of any class, such as a view controller or a dedicated data source class that perhaps just inherits from NSObject. In order for the table view to know whether an object is suitable as a data source, it’s important to be able to declare that the object implements the necessary methods. The description above is essentially related to which feature of Objective-C programming language ?

86.
Which of the following is the base class of all objects in Objective-c ?

NSObject

NSRoot

NSClass

NSInstance

Answer

Correct Answer: NSObject

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

87.
Objective-C provides a range of methods to work with NSNumber. Which of the following methods creates and returns an NSNumber object containing a given value, treating it as an NSInteger.

`+ (NSNumber *)numberWithInt:(int)value`

`- (NSInteger)integerValue`

`+ (NSNumber *)numberWithInt:(NSInteger)value`

`+ (NSNumber *)numberWithInteger:(NSInteger)value `

Answer

Correct Answer: `+ (NSNumber *)numberWithInteger:(NSInteger)value `

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

88.
While calling a function by reference, it will copy the actual value of an argument into the formal parameter of the function. In this case, changes made to the parameter inside the function have no effect on the argument. Is the statement above True ?

Yes

Answer

Correct Answer: No

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

89.
Objective-C is a general-purpose, object-oriented programming language that adds Smalltalk-style messaging to the (...) programming language. This is the main programming language used by Apple for the OS X and iOS operating systems and their respective APIs, Cocoa and Cocoa Touch.

Java

C++

Frotran

Answer

Correct Answer: C

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

90.
What happens when the following code executes?
Ball *ball = [[[[Ball alloc] init] autorelease] autorelease];

It will be added twice to the autorelease pool and decrement reference count twice

It will be added ince to the autorelease pool and decrement reference count twice

It will crash

None of the above

Answer

Correct Answer: It will crash

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

91.
Which of the following is correct (legal) floating-point literal ?

314159E-5L

510E

210f

.e55

Answer

Correct Answer: 314159E-5L

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

92.
In Objective-C, a derived class can access all the private members of its base class if it's defined in the interface class, but it cannot access private members that are defined in the implementation file. Is the statement above correct ?

Yes

Answer

Correct Answer: Yes

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

93.
In Objective-C, retain counts are the way in which memory is managed in Objective-C. When you create an object, it has a retain count of 1. When you send an object a (...) message, its retain count is incremented by 1. When you send an object a (...) message, its retain count is decremented by 1.

retain, release

release, retain

autorelease, retain

autorelease, release

Answer

Correct Answer: retain, release

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

94.
The (...) method can be used to see if an object belongs to a class that implements a particular protocol.

conformsToProtocol:

acceptsToProtocol:

followsToProtocol:

implementsToProtocol:

Answer

Correct Answer: conformsToProtocol:

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

95.
(...) is an abstractClass which represents a stream of data. They are used in Archiving and Unarchiving objects. (...) objects are usually used in a method that is being implemented so that the class conforms to the protocol.

NSCoder

NSData

NSObject

NSStream

Answer

Correct Answer: NSCoder

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

96.
In Objective-C programming, error handling is provided with (...) class available in Foundation framework. An (...) object encapsulates richer and more extensible error information than is possible using only an error code or error string. The core attributes of an (...) object are an error domain (represented by a string), a domain-specific error code and a user info dictionary containing application specific information.

NSException

NSError

NSRuntimeError

Exception

Answer

Correct Answer: NSError

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

97.
Two distinct types of problems can arise while an iOS or OS X application is running. Exceptions represent programmer-level bugs like trying to access an array element that doesn’t exist. They are designed to inform the developer that an unexpected condition occurred. Since they usually result in the program crashing, exceptions should rarely occur in your production code. On the other hand, errors are user-level issues like trying load a file that doesn’t exist. Because errors are expected during the normal execution of a program, you should manually check for these kinds of conditions and inform the user when they occur. Most of the time, they should not cause your application to crash. Is the statement above correct ?

Yes

Answer

Correct Answer: Yes

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

98.
In Objective-C, Exceptions can be handled using the standard a common pattern found in most other high-level programming languages. First, you need to place any code that might result in an exception in an (...) block. Then, if an exception is thrown, the corresponding (...) block is executed to handle the problem. The (...) block is called afterwards, regardless of whether or not an exception occurred.

`@ catch(), @try, @finally`

`@try, @throw, @catch()`

`@finally, @catch(), @throw `

`@try, @catch(), @finally`

Answer

Correct Answer: `@try, @catch(), @finally`

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

99.
Which of the following is not a property of NSError class?

domain

code

reason

userInfo

Answer

Correct Answer: reason

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

100.
In Objective-C, a category is a group of related methods for a class, and all of the methods defined in a category are available through the class as if they were defined in the main interface file. Instead of the normal @interface declaration, we include the category name in (...) after the class name we're extending.

`{}`

`()`

`<>`

`[]`

Answer

Correct Answer: `()`

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

101.
If you start a class definition that conforms to a specified (...), you will not need to relist all the methods you will implement for that protocol in the @interface section.

102.
(...) are used by Cocoa and Cocoa Touch objects for a variety of different situations. For example, the table view classes (NSTableView for OS X and UITableView for iOS) both use a data source object to supply them with the necessary information. Both define their own data source (...); both table view classes also allow you to set a delegate object, which again must conform to the relevant NSTableViewDelegate or UITableViewDelegate (...). The delegate is responsible for dealing with user interactions, or customizing the display of certain entries.

Protocol

103.
What's the hierarchy of UIButton until NSObject ?

UIButton >> UIResponder >> UIControl >> UIView >> NSObject

UIButton >> UIControl >> UIView >> UIResponder >> NSObject

UIButton >> UIView >> UIControl >> UIResponder >> NSObject

UIButton >> UIControl >> UIResponder >> UIView >> NSObject

Answer

Correct Answer: UIButton >> UIControl >> UIView >> UIResponder >> NSObject

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

104.
Which of the following contains the INCORRECT definition of a Predefined Macro ?

`__STDC__`: This contains the current line number as a decimal constant.

`__FILE__ `: This contains the current filename as a string literal.

`__TIME__ `: The current time as a character literal in "HH:MM:SS" format

`__DATE__ `: The current date as a character literal in "MMM DD YYYY" format

Answer

Correct Answer: `__STDC__`: This contains the current line number as a decimal constant.

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

105.
In (...), the system uses the same reference counting system as (...), but it inserts the appropriate memory management method calls for us at compile-time.

MRR, ARC

ARC, MRR

ARC, Garbage Collection

MRR, Garbage Collection

None of the above

Answer

Correct Answer: ARC, MRR

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

106.
Which of the following contains the INCORRECT definition of a preprocessor directive ?

`#define`: Substitutes a preprocessor macro

`#include`: Inserts a particular header from another file

`#undef`: Undefines a preprocessor macro

`#error`: Issues special commands to the compiler using a standardized method

`#ifdef`: Returns true if this macro is defined

Answer

Correct Answer: `#error`: Issues special commands to the compiler using a standardized method

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

107.
While calling a function by reference, it will copy the address of an argument into the formal parameter. Inside the function, the address is used to access the actual argument used in the call. This means that changes made to the parameter affect the argument. Is the statement above True ?

Yes

Answer

Correct Answer: No

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

108.
Which of the following contains the INCORRECT definition of a bitwise operator ?

`&` : Binary AND Operator copies a bit to the result if it exists in both operands.

`|` : Binary OR Operator copies a bit if it exists in either operand.

`^`: Binary Ones Complement Operator is unary and has the effect of 'flipping' bits.

`<<`: Binary Left Shift Operator. The left operands value is moved left by the number of bits specified by the right operand.

Answer

Correct Answer: `^`: Binary Ones Complement Operator is unary and has the effect of 'flipping' bits.

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

109.
What is category in Objective-C?

Category is a child class

Category is used to define additional methods of an existing class

Category is the functional extension of the class

Answer

Correct Answer: Category is used to define additional methods of an existing class

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

110.
What is the difference between #import and #include?

There is no difference

The #include allows you to include the same file many times while #import ensures that the preprocessor only includes a file once

The former checks the current directory as well as the system directories

Answer

Correct Answer: The #include allows you to include the same file many times while #import ensures that the preprocessor only includes a file once

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

111.
Where is a MKAnnotationView used?

On a Map View

On a pinView

On a GeoLocation View

None of the above

Answer

Correct Answer: On a Map View

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

112.
Which is the most proper answer about the difference between nil and NULL?

nil is a constant and NULL is an object

nil and NULL both are constants

nil and NULL is same in their purpose and using

nil is an object that can receive messages but NULL is a constant

Answer

Correct Answer: nil is an object that can receive messages but NULL is a constant

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

113.
The property attribute that causes the setter to store a strong reference to the assigned value is called:

instance

Method

NSObject

Strong

Answer

Correct Answer: Strong

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

114.
The part of an Objective-C class specification that declares its public interface which includes its superclass name & instances variables and public-method prototypes is called:

interface

public

protocol

inheritance

Answer

Correct Answer: interface

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

115.
What is the difference between the unsigned int and the NSUInteger?

It depends on the processor

NSUInteger is an Objective-C class

NSUInteger is a 64bits unsigned integer

None of the above

Answer

Correct Answer: NSUInteger is an Objective-C class

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

116.
Look at below code and tell which is correct.
(id) init { if ( self == [super init] ) { [self setCaption:@"Default Caption"]; } return self; }

No problem, everything is correct

if ( self == [super init] )

Init should be void function

Answer

Correct Answer: No problem, everything is correct

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

117.
Look at below code and tell what the problem could be:
NSNumber value1 = [[NSNumberalloc] initWithFloat:8.15]; NSNumber value2 = [NSNumber numberWithFloat:8.29]; … … … [value1 release]; [value2 release];

No problem, everything is correct

[value2 release];

Value1 and value2 should be initialized after allocating

Not sure

Answer

Correct Answer: Value1 and value2 should be initialized after allocating

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

118.
What is the name of the root class in Objective-C?

NSObject

adopt

protocol

Cocoa

Answer

Correct Answer: NSObject

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

119.
Two additional foundational building blocks of Objective-C distinct from data and procedure type foundations: _____ and Categories/Extensions?

Stack

Protocols

Encapsulation

Cycles

Answer

Correct Answer: Protocols

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

120.
What is a class object?

Class Object is an implementation of a Class that has method and property

Class Object can be said as an instance of built version of the class

Class Object is an object named as Class

Answer

Correct Answer: Class Object is an implementation of a Class that has method and property

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

121.
How do you free an object?

[obj release]

free(obj)

[obj free]

None of the above

Answer

Correct Answer: [obj release]

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

122.
What is the difference between the unsigned int and the NSUInteger?

It depends on the processor

NSUInteger is an Objective-C class

NSUInteger is a 64bits unsigned integer

None of the above

Answer

Correct Answer: It depends on the processor

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

123.
What can you do with categories?

Add instance variables to a class without subclassing it

Add methods to a class without subclassing it

Override methods of a class without subclassing it

None of the above

Answer

Correct Answer: Add methods to a class without subclassing it
Override methods of a class without subclassing it

Note: This question has more than 1 correct answers

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

124.
What can be linked to an Obj-C program without any particular process?

C libraries

Java jar files

C++ libraries

scripts

Executables

Answer

Correct Answer: C libraries
C++ libraries

Note: This question has more than 1 correct answers

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

125.
What is an IMP?

A special type used for computation

An alias for SEL

A preprocessor directive defined to the implementation name

The C type of a method implementation pointe

None of the above

Answer

Correct Answer: The C type of a method implementation pointe

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

126.
Which of the following is incorrect?

[self release]

[super release]

[AClass release]

They are all correct

Answer

Correct Answer: [AClass release]

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

127.
Protocols are like classes; they can inherit

True

False

Answer

Correct Answer: True

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

128.
Which of the following declares a protocol?

@proto ProtocolName

protocol ProtocolName {};

@protocol ProtocolName

@interface <ProtocolName>

@interface ProtocolName::Protocol

Answer

Correct Answer: @protocol ProtocolName

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

129.
How do you include the root “Object” class?

#include <Object.h>

#include <objc/Object.h>

#include <Object/Object.h>

#include <ROOT.h>

It depends on the compiler

Answer

Correct Answer: It depends on the compiler

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

130.
What is a protocol?

A class that uses functions instead of methods

A method signature

A class signature

An interface without an implementation

None of the above

Answer

Correct Answer: An interface without an implementation

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

131.
What can be used as Object instance variables?

int

structures

pointers

unions

None of the above

Answer

Correct Answer: int
structures
pointers
unions

Note: This question has more than 1 correct answers

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

132.
What is a @finally block?

A block that is executed when the program quites

A block that is executed within a dynamic library when it’s unloaded

A block of code that is run whenever an exception is thrown or not

None of the above

Answer

Correct Answer: A block of code that is run whenever an exception is thrown or not

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

133.
How do you throw an exception?

raise Exception

@throw exception

RAISE exception

THROW exception

None of the above

Answer

Correct Answer: @throw exception

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

134.
What’s the difference between copy and deepCopy?

They are the same

deepCopy doesn’t exist

copy creates a copy at the first level, while deepcopy copies the instance variables

copy creates a proxy object, while deepCopy allocate a new object.

None of the above

Answer

Correct Answer: copy creates a copy at the first level, while deepcopy copies the instance variables

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

135.
Can you send messages to nil?

Yes

Answer

Correct Answer: Yes

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

136.
What is the isa variable in objects?

Object size

Object memory footprint

Object class identification

Object serial number

None of the above

Answer

Correct Answer: Object class identification

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

137.
Which of the following does not happen when you throw an exception in a @synchronized block?

The object is deallocated

The object is unlocked

An exception is thrown

None of the above

Answer

Correct Answer: The object is deallocated

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

138.
In which version of Objective-C did the properties system appear?

3.0

2.5

2.0

1.5

1.0

Answer

Correct Answer: 2.0

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

139.
Which of the following is not recommended?

Adding an (id)sender argument to methods

Using static variables inside methods

Using C code inside Obj-C methods

None of the above

Answer

Correct Answer: Using static variables inside methods

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

140.
Which of the following can be inherited?

141.
What is an autoreleased object?

A C Object

A static object

An object that is garbage collected

An object that will be released when the current AutoreleasePool is deallocated.

None of the above

Answer

Correct Answer: An object that will be released when the current AutoreleasePool is deallocated.

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

142.
Can a method be declared to accept a variable number of arguments?

Yes

Answer

Correct Answer: Yes

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

143.
What is the default visibility for instance variables?

@private

@package

@public

@protected

None of the above

Answer

Correct Answer: @protected

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

144.
Which of the following is false?

Method lookup is done at runtime

When a method is called, the send is automatically available as the sender variable, like self or super

Messages can be sent to nil

Methods in static libraries must be present at link time

Answer

Correct Answer: When a method is called, the send is automatically available as the sender variable, like self or super

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

145.
What are @try and @catch?

Exception handlers

Exceptions

Exception keywords

All of the above

Answer

Correct Answer: Exception keywords

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

146.
What is not supported in Obj-C?

Recursive method call

Variable argument count to method

Byte manipulation

Method argument default value

None of the above

Answer

Correct Answer: Method argument default value

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

147.
Is the following code a correct allocation?
MyClass myObj;
[&myObj aMessage];

Yes

Answer

Correct Answer: No

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

148.
What comments are supported in Obj-C?

//Line comments

/* Block comments */

# Line comments

; Line comments

–[[ block comments ]]

Answer

Correct Answer: //Line comments
/* Block comments */

Note: This question has more than 1 correct answers

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

149.
What is true regarding @public?

It doesn’t exist in Objective-C

It breaks encapsulation

It can be used only on sigleton objects.

None of the above

Answer

Correct Answer: It breaks encapsulation

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

150.
What does the following imply?
Worker *ceo = [[Worker alloc] init];
ceo->boss = nil;

That the ceo object is statically typed

That the boss instance variable is declared @protected

That the boss instance variable is declared @public

That the ceo is in fact a structure

This code is not correct

Answer

Correct Answer: That the ceo object is statically typed
That the boss instance variable is declared @public

Note: This question has more than 1 correct answers

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

151.
A method can be tagged to be called only by a specific class and its subclasses.

True

False

Answer

Correct Answer: False

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

152.
When using the garbage collector, which method, that is normally called without the collector, is not called on your objects where they are collected?

free

dealloc

destroy

uninit

Answer

Correct Answer: dealloc

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

153.
How do you allocate an object?

MyClass *obj = malloc(sizeof(MyClass));

MyClass *obj = [MyClass new];

None of the above

Answer

Correct Answer: MyClass *obj = malloc(sizeof(MyClass));
MyClass *obj = malloc(sizeof(MyClass));
MyClass *obj = malloc(sizeof(MyClass));

Note: This question has more than 1 correct answers

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

154.
What is true regarding @protected?

The instance variable is accessible within the class that declares it and within classes that inherit it

The instance variable is accessible everywhere

The instance variable is accessible only with the class that declares it.

This is analogous to private_extern for variables and functions. Any code outside the class implementation’s image that tries to use the instance variable will get a link error

None of the above

Answer

Correct Answer: The instance variable is accessible within the class that declares it and within classes that inherit it

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

155.
What type of variable do you need to use to implement singletons?

static

auto

const

volatile

Answer

Correct Answer: static

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

156.
Which C feature is not supported in Obj-C?

Bitfields

Compound literals

Structures

C arrays

Support is compiler dependant

Answer

Correct Answer: Support is compiler dependant

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

157.
What is nil?

The null object

The null class

It doesn’t exist

None of the above

Answer

Correct Answer: The null object

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

158.
In Obj-C 2.0, what do the fast enumeration protocols rely on to provide fast Enumerations?

C arrays

Java Vectors

Ruby hash

Obj-C Array

None of the above

Answer

Correct Answer: C arrays

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

159.
What is true regarding strings?

C string literals are automatically mapped to objects

C string literals can be used in Obj-C

Obj-C strings are not of static storage

Obje-C strings are like C strings

Answer

Correct Answer: C string literals can be used in Obj-C

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

160.
In which version of Objective-C did the fast enumeration system appear?

2.0

1.5

1.0

3.0

Answer

Correct Answer: 2.0

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

161.
A class can conform to only one protocol?

True

False

Answer

Correct Answer: False

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

162.
What is a category?

A namespace

A category is a way to add instance variables to a class which already exists

A category is a group of classes

A category is a way to add methods to a class which already exists

None of the above

Answer

Correct Answer: A category is a way to add methods to a class which already exists

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

163.
What happens if you release an unretained object twice?

Nothing, too many releases are handled correctly

Undefined behaviour

MemoryException is raised

None of the above

Answer

Correct Answer: Undefined behaviour

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

164.
What does Obj-C not support?

Instance variable

Class variables

Static variables

Automatic variables

Answer

Correct Answer: Class variables

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

165.
Which of the following is the fastest?

@synchronized

Explicit locking

Condition locking

Mutex implicit locking

Answer

Correct Answer: Explicit locking

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

166.
What is true regarding C functions inside .m files?

They can contain Obj-C code

They are slower than if in a .c files

They cannot use C libraries

They can be static

Answer

Correct Answer: They can contain Obj-C code
They can be static

Note: This question has more than 1 correct answers

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

167.
If you need to allocate custom memory, in which method will you do so?

+alloc

–alloc

+init

–init

None of the above

Answer

Correct Answer: –init

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

168.
What is the Obj-C runtime?

A C library

A compiler

A language

A dynamic loader

Answer

Correct Answer: A C library

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

169.
What happens if two categories define methods with the same names for the same class?

The code won’t compile

At runtime, either method will be called

A runtime exception will be thrown

None of the above

Answer

Correct Answer: At runtime, either method will be called

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

170.
What is true regarding messaging?

Messaging is static and messages are replaced by function call at compile time

Messaging is fully dynamic, which means you can compile some code that sends a message to a class that doesn’t implement it, and add a category later, in a dynamic library for example

Messaging is only a syntax sugar to call functions

None of the above is true

Answer

Correct Answer: Messaging is fully dynamic, which means you can compile some code that sends a message to a class that doesn’t implement it, and add a category later, in a dynamic library for example

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

171.
A class can have two methods with the same name, but with different argument types?

True

False

Answer

Correct Answer: False

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

172.
What can you use to avoid the msgSend function overhead?

SEL

IMP

You can’t use anything

None of the above

Answer

Correct Answer: IMP

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

173.
What is #import?

A namespace import rule

A namespace definition

A recursive include

C preprocessor construct to avoid multiple inclusions of the same file

None of the above

Answer

Correct Answer: C preprocessor construct to avoid multiple inclusions of the same file

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

174.
Which of the following creates a class that conforms to a protocol?

@interface ClassName [ProtocolName]

@interface ClassName < ProtocolName

@interface ClassName::ProtocolName

@interface ClassName(ProtocolName)

Answer

Correct Answer: @interface ClassName [ProtocolName]
@interface ClassName [ProtocolName]

Note: This question has more than 1 correct answers

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

175.
Can an exception caught in @catch be re-thrown?

Yes

Answer

Correct Answer: Yes

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

176.
What class specifiers are supported?

FINAL

STATIC

FAST

ITERATIVE

There is no such thing as class specifiers.

Answer

Correct Answer: There is no such thing as class specifiers.

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

177.
What will be the output of the following code?
static int
a (void)
{
printf ("a\n");
return 0;
}
static int
b (void)
{
printf ("b\n");
return 1;
}
static int
c (void)
{
printf ("c\n");
return 2;
}
int main (int argc, const char *argv[])
{
printf ("%d %d %d", a (), b (), c ());
return 0;
}

a b c 0 1 2

a b c 2 1 0

c b a 0 1 2

c b a 2 1 0

None of the above

Answer

Correct Answer: c b a 0 1 2

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

178.
What is a SEL?

A selection

The C type of a message selector

The C type of a class

A pointer to a method

None of the above

Answer

Correct Answer: The C type of a message selector

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

179.
What is the id type?

A generic C type that Objective-C uses for an arbitrary object.

A memory address type

A type to hold serialized objects.

The type used for Classes

Noe of the above.

Answer

Correct Answer: A generic C type that Objective-C uses for an arbitrary object.

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

180.
What is the C type used to work with objects in Obj-C?

int

structure

pointer

array

Answer

Correct Answer: pointer

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

181. What will be logged? int x = 1; __block int y = 1; void (^test)(void) = ^{ NSLog(@"%i, %i", x, y); }; x = 2; y = 2; test();

2, 1

1, 2

2, 2

1, 1

Answer

Correct Answer: 1, 2

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

182. What is true regarding messaging?

None of the above is true

Messaging is fully dynamic, which means you can compile some code that sends a message to a class that doesn't implement it, and add a category later, in a dynamic library for example

Messaging is only a syntax sugar to call functions

Messaging is static and messages are replaced by function call at compile time

Answer

Correct Answer: Messaging is fully dynamic, which means you can compile some code that sends a message to a class that doesn't implement it, and add a category later, in a dynamic library for example

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

183. Which of the following is the fastest?

Explicit locking

Mutex implicit locking

@ Synchronized

Condition locking

Answer

Correct Answer: Mutex implicit locking

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

184. A class can have two methods with the same name, but with different argument types.

False

True

Answer

Correct Answer: False

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

185. Why should you use an autorelease pool ?

To pre-allocate memory for speeding up object creation

To avoid memory presure when creating a lot of autoreleased object (for example in a loop)

To inform ARC that the objects created inside the pool should be autoreleased

You should not use autorelease pool, it's a bad practice, especially under ARC

Answer

Correct Answer: To avoid memory presure when creating a lot of autoreleased object (for example in a loop)

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

186. Which of the following statements is correct?

@property(readwrite,copy,atomic)NSInteger value;

@property(readwrite,retain,atomic)NSInteger value;

@property(readwrite,assign,copy,atomic)NSInteger value;

@property(readwrite,retain,atomic,copy)NSInteger value;

none of the above

Answer

Correct Answer: @property(readwrite,retain,atomic)NSInteger value;

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

187. What сan you use to avoid msgSend function overhead?

None of these

You can't use anything

IMP

SEL

Answer

Correct Answer: IMP

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

188. What happens if two categories define methods with the same names for the same class?

None of the above

At runtime, either method will be called

A runtime exception will be thrown

The code won't compile

Answer

Correct Answer: At runtime, either method will be called

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

189. What happens at runtime with the following: NSMutableString *tempString = [NSMutableString stringWithString:@"1"]; dispatch_sync(dispatch_get_main_queue(), ^{ [tempString appendString:@"2"]; NSLog(@"%@", tempString); }); [tempString appendString:@"3"];

Log prints "123" and continues as usual.

Log prints "12" and then we will have a deadlock here because the main queue will block

Log doesn't print anything. It's a deadlock here because the main queue will block on the call to dispatch_sync

Log prints "132" and continues as usual.

Answer

Correct Answer: Log doesn't print anything. It's a deadlock here because the main queue will block on the call to dispatch_sync

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

190. A UIView is a superclass of:

UIViewController

UIWindow

UILabel

UIScreen

UIImage

Answer

Correct Answer: UILabel

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

191. Which of these methods is NOT invoked by the runtime itself?

-dealloc

-doesNotRecognizeSelector:

+load

+initialize

-forwardInvocation:

Answer

Correct Answer: -dealloc

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

192. How is a selector typically represented in memory?

As a pointer to a C struct.

As a null terminated C string.

As an Objective-C object.

As a unique 32-bit number.

Answer

Correct Answer: As a null terminated C string.

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

193. What's the difference between nil and NULL?

nil is literal null value for Objective-C instances. NULL is literal null value for Objective-C classes

nil is literal null value for Objective-C instances. NULL is object used to represent null

NULL is literal null value for Objective-C instances. nil is literal null value for C pointers

nil is literal null value for Objective-C instances. NULL is literal null value for C pointers

they are the same thing

Answer

Correct Answer: nil is literal null value for Objective-C instances. NULL is literal null value for C pointers

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

194. A UITableViewController's tableview must have its delegate explicitly set by the developer.

FALSE

TRUE

Answer

Correct Answer: FALSE

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

195. How to restore Consumable In-App Purchases?

Use Store Kit’s addPayment: method

Consumable In-App Purchases are not to be restored

Use Store Kit’s restoreCompletedTransactions method

Use Store Kit’s initWithProductIdentifiers: method

Use Store Kit’s finishTransaction: method

Answer

Correct Answer: Consumable In-App Purchases are not to be restored

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

196. What is the last chance for an object to handle a message?

+instancesRespondToSelector:

-respondsToSelector:

-forwardingTargetForSelector:

-forwardInvocation:

+resolveInstanceMethod:

Answer

Correct Answer: -forwardInvocation:

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

197. What can you say about the code: NSString * str = [NSString stringWithFormat:@""]; [str release];

None of these

It is correct, everything will work fine

it will cause a SIGABRT when the enclosing method ends

It will cause the string to be released twice with undefined consequences when the surrounding autorelease pool is emptied

It will cause a SIGSEGV at [str release];

Answer

Correct Answer: It will cause the string to be released twice with undefined consequences when the surrounding autorelease pool is emptied

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

198. What happens at runtime with the following: dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0); dispatch_apply(10, queue, ^(size_t index) { NSLog(@"%zu", index); });

Log prints "12345678910"

We won't have persistent result

Log prints "9876543210"

Log prints "0123456789"

Answer

Correct Answer: We won't have persistent result

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

199. What class method is used to make an NSArray from NSData class?

NSData dataWithContentsOfFile:

NSFileManager defaultManager

NSArray arrayWithObject:

NSKeyedUnarchiver unarchiveObjectWithData:

Answer

Correct Answer: NSKeyedUnarchiver unarchiveObjectWithData:

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

200. What do you use for an outgoing TCP connection?

(none of these)

NSTCPProtocol

NSStream

NSUrlStream

Answer

Correct Answer: NSStream

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

201. Which method, if defined, is guaranteed to be called once -- and only once -- when a class is first referenced?

+ (Class) alloc;

+ (id) init;

+ (void) initialize;

+ (id) alloc;

+ (void) init;

Answer

Correct Answer: + (void) initialize;

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

202. If you wanted to override the default alloc method in a class Foo, what would be the appropriate way to declare it?

- (id) alloc;

- (Foo *) alloc;

+ (id) alloc;

+ (Foo *) alloc;

It's not possible to override alloc.

Answer

Correct Answer: + (id) alloc;

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

203. How do you convert a Core Image color to a UIColor?

CIColorValue:

UIColorValue:

UIColorWithCIColor:

colorWithCIColor:

Answer

Correct Answer: colorWithCIColor:

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

204. True or False? Key value coding is used to indirectly access an object's attributes using indexes.

False

True

Answer

Correct Answer: False

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

205. How do you add a brightening effect on a CoreImage?

CIAdditionCompositing

Set the alpha

CIBrighten

Answer

Correct Answer: CIAdditionCompositing

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

206. What protocol is used to create an action object?

None of These

NSAction

CAAction

CoreAnimation

Answer

Correct Answer: CAAction

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

207. What is not supported in Objective-C

Byte manipulation

Variable argument count to method

Recursive method call

Method argument default value

Answer

Correct Answer: Method argument default value

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

208. In Core Data, what is the name of the object representation for the database schema?

NSManagedObjectModel

NSManagedObject

NSEntityDescription

NSManageObjectContext

Answer

Correct Answer: NSManagedObjectModel

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

209. What does the following code do, assume ARC is enabled? NSArray *myArray; for (int i = 0; i < 10; i++){ @autoreleasepool { myArray = [[NSArray alloc]init]; } }

For each iteration of the loop a new array is allocated and will leak memory.

For each iteration of the loop a new array is allocated only.

For each iteration of the loop a new array is allocated and will be released at the end of the loop.

For each iteration of the loop a new array is allocated and released.

Answer

Correct Answer: For each iteration of the loop a new array is allocated and released.

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

210. What happens if you use fgets and do not give it a size smaller than the buffer?

It will clip its size automatically

It will use the size of the object as its size

It will overwrite the data past the size

None of these

Answer

Correct Answer: It will overwrite the data past the size

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

211. how can we return multiple values from function?

tuple

not possible

void*

Answer

Correct Answer: tuple

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

212. True or False? You should use NSHost when connecting to a specific host.

True

False (You should use CFHost)

Answer

Correct Answer: False (You should use CFHost)

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

213. Which of these classes is NOT a root class?

NSString

NSObject

NSMessageBuilder

NSProxy

NSZombie

Answer

Correct Answer: NSString

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

214. What is the object.toString equivalent in objective-c?

[NSObject toString]

[NSObject getDetails]

[NSObject description]

[NSObject getDescription]

[NSObject stringWithFormat]

Answer

Correct Answer: [NSObject description]

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

215. Objective-C methods with certain names (“init”, “alloc”, etc.) always return objects that are an instance of the receiving class’s type; such methods are said to have a “related result type”. A method with a related result type can be declared by using:

instancetype

resultType

NSRelatedType

returntype

Answer

Correct Answer: instancetype

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

216. How can you temporarily disable layer actions in a Core Animation?

Using the CATransaction class

Using the CAStopAnimation class

Using the CAExit class

Using the CAStop class

Answer

Correct Answer: Using the CATransaction class

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

217. What are the two types of predicates?

Filter and Exclusion

Comparison and Compound

Expression and Operator

Answer

Correct Answer: Comparison and Compound

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

218. What is a persistent object store?

It is retained database objects

It represents an external file of persisted data

It is the schema for your object

It is the relationships between tables in your data

Answer

Correct Answer: It represents an external file of persisted data

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

219. True or False? You can perform operator overloading in Objective-C.

False

True

Answer

Correct Answer: False

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

220. The proper typedef syntax for an Objective-C block that takes an NSArray and returns an NSString is

typedef NSArray *(^aBlock)(NSString *);

typedef aBlock^ = (NSString *)(NSArray *);

typedef NSString *(^aBlock)(NSArray *);

typedef void(^aBlock)(void);

Answer

Correct Answer: typedef NSString *(^aBlock)(NSArray *);

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

221. What is the difference between [Foo new] and [[Foo alloc] init]?

New is significantly faster than alloc + init.

New does not exist in Objective-C.

None, they perform the same actions.

New will not always initialize the object.

Answer

Correct Answer: None, they perform the same actions.

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

222. True or False? The format for a NSPredicate is the same as a Regular Expression.

False

True

Answer

Correct Answer: False

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

223. What is Objective-C's language design based on?

C and Cocoa.

C and Objectivity.

C and C++.

C and Smalltalk.

C and BCPL.

Answer

Correct Answer: C and Smalltalk.

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

224. What can happen if you use self inside a block?

self can become a dangling pointer

By the time the block executes, self can be pointing to a different object

You can create a retain cycle

None of the above

Answer

Correct Answer: You can create a retain cycle

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

225. What is a proper format for calling an asynchronous function?

[NSOperationDispatchAsync dispatch_asyncWithBlock: ^{ // code }];

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^{ // code });

[dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), // code ];

[dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^{ // code })];

Answer

Correct Answer: dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^{ // code });

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

226. What is the 'print object' command in the debugger window?

-l

Answer

Correct Answer: po

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

227. If you do not declare a return type for a method definition, what is the default return type?

No return type

*NSString

Answer

Correct Answer: id

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

228. In Core Data, what is the name of an object representation of a record?

NSManagedObject

NSManageObjectContext

NSManagedObjectModel

NSEntityDescription

Answer

Correct Answer: NSManagedObject

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

229. What happens at runtime with the following: NSObject* object = nil; NSObject* object2 = [object copy]; NSLog(@"%@", object2);

object2 is instantiated as an NSObject with nil values

Log prints "(null)" and continues as usual.

Application crashes with "SIGABRT: object has been derferenced" error

Application continues, but issues "cannot access nil object reference" warning

Answer

Correct Answer: Log prints "(null)" and continues as usual.

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

230. Assume ARC is enabled... What would be another way to write this: NSArray *array = [NSArray arrayWithObjects:@"One", @"Two", @"Three",nil];

NSArray *array = @{@"One", @"Two", @"Three"};

NSArray *array = @[@"One", @"Two", @"Three"];

NSArray *array = [@"One", @"Two",@"Three"];

NSArray *array = {@"One", @"Two",@"Three"};

Answer

Correct Answer: NSArray *array = @[@"One", @"Two", @"Three"];

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

231. Are integers full-fledged objects in Objective-C?

Integers are only partial objects in Objective-C (e.g. do not support any user defined methods).

No, they are not objects at all.

Yes.

Yes, but only if you first cast them as id's, e.g. (id) 123.

Answer

Correct Answer: No, they are not objects at all.

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

232. What class will allow you to use one or more blocks concurrently?

NSConcurrentBlock

NSBlock

NSBlockOperation

NSConcurrency

Answer

Correct Answer: NSBlockOperation

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

233. Does Objective-C have constructors and destructors?

It depends on the object

No, you use init and dealloc on Objective-C

Yes

Only NSStrings do

Answer

Correct Answer: No, you use init and dealloc on Objective-C

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

234. True or False? Strings are one of the most common sources of buffer overflow attacks.

False

True

Answer

Correct Answer: True

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

235. what does this code produce? [NSString] *myString = @"Hello World";

gets SIGABRT while executing the application

none of the above

An Error during compile

it put the value Hello World into a string named myString

makes the pointer to myString equal to the pointer of the new created object with @"hello world"

Answer

Correct Answer: An Error during compile

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

236. Can an exception caught in @ catch be re-thrown?

Yes

Answer

Correct Answer: Yes

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

237. let a:int=5 a=10 this code is true of false?

true

false

Answer

Correct Answer: false

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

238. Which of the following accesses a variable in structure b?

b-var;

b.var;

b>var;

b->var;

Answer

Correct Answer: b.var;

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

239. What framework is KVO (key value observing) a part of?

UIKit

CoreData

Foundation

Answer

Correct Answer: Foundation

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

240. Using UIViewController containment, which one of the following statements is true:

Every viewcontroller can handle the loading and unloading of other viewcontroller.

The root viewcontroller handles loading and unloading its child viewcontrollers.

Answer

Correct Answer: The root viewcontroller handles loading and unloading its child viewcontrollers.

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

241. How can you add a new method foo to an existing class Bar?

Define a C function foo and then send Bar the extend:withSelector: message, e.g. [Bar extend: foo withSelector: @selector(foo:)].

Both "extend" options are correct.

Make a category, e.g. @interface Bar(Foo).

It's not possible.

Send Bar the "extend:" message, e.g. [Bar extend: foo].

Answer

Correct Answer: Make a category, e.g. @interface Bar(Foo).

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

242. Which framework lets you determine the current location or heading associated with a device?

NSLocation

CFLocation

CoreLocation

MapKit

LocationKit

Answer

Correct Answer: CoreLocation

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

243. True or False? A method and a variable can have the same name in Objective-C.

False

True

Answer

Correct Answer: True

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244. What is used to sort Core Data results?

NSCoreDataSort

NSSortDescriptor

NSSort

[self sort]

Answer

Correct Answer: NSSortDescriptor

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

245. How do you get the Unicode character set of a Core Text font?

CTFontCopyCharacterSet

CTFontCopyFamilyName

CTFontCopyDisplayName

Answer

Correct Answer: CTFontCopyCharacterSet

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

246. What is the name of the type of SQL Database that iOS Supports?

SQLite

SQL

NoSql

MySql

Answer

Correct Answer: SQLite

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

247. Which of the following is an object?

float

int

NSNumber

double

Answer

Correct Answer: NSNumber

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

248. Where is a MKAnnotationView used?

In a button

On a cell

On a Map View

On a table view

Answer

Correct Answer: On a Map View

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

249. What is a delegate?

A delegate holds the type of data a variable stores

A delegate allows one NSObject to send messages to another NSObject, and listen to those messages

A delegate is a UIView

A delegate is a variable

Answer

Correct Answer: A delegate allows one NSObject to send messages to another NSObject, and listen to those messages

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

250. ARC means?

Artificial Reference Counting

Application Reference Collection

Access Reference Collation

Angular Reference Courting

Automatic Reference Counting

Answer

Correct Answer: Automatic Reference Counting

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

251. What does an Objective-C string literal look like?

"foo"

NSString("foo")

$"foo"

@"foo"

#"foo"

Answer

Correct Answer: @"foo"

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

252. If you define a new class called Foo which inherits from NSObject, how do you create a new instance of it?

Foo *temp = new Foo();

Foo *temp = [[Foo alloc] init];

Foo *temp = System.Create(Foo);

Foo *temp = [Foo init];

Foo *temp = Make Instance of Foo;

Answer

Correct Answer: Foo *temp = [[Foo alloc] init];

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

253. What framework does the class UIButton come from?

CoreGraphics

Foundation

OpenGLES

EventKit

UIKit

Answer

Correct Answer: UIKit

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

254. Which of the following is a Singleton?

[NSArray array]

[NSFileManager defaultManager]

Answer

Correct Answer: [NSFileManager defaultManager]

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

255. How do you concatenate two NSStrings foo and NSString bar to form a new NSString *baz?

baz = [foo stringByAppendingString: bar];

baz = [foo concat: bar];

baz = foo + bar;

baz = [foo appendString: bar];

baz = foo & bar;

Answer

Correct Answer: baz = [foo stringByAppendingString: bar];

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

256. What does the "id" type mean?

This is a type for a specific object of class id

This is a type for strings

This is the general type for any kind of object regardless of class

Answer

Correct Answer: This is the general type for any kind of object regardless of class

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

257. To have an IOS app Screen Design we used which of the following tool?

None of above

Interface Xcode

Interface Designer

Interface builder

Instruments

Answer

Correct Answer: Interface builder

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

258. What is the method for adding KVO to your app?

addKVO:forKey:

addObserver:forKeyPath:options:context

addListener:withContext:andObject:

Answer

Correct Answer: addObserver:forKeyPath:options:context

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

259. What type of object is this under XCode 4.5: @[rabbit, chicken, owl]

NSDictionary

NSString

SQLite schema

NSArray

Answer

Correct Answer: NSArray

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

260. How do you free an object?

free(obj)

None of the above

[obj free]

[obj release]

[obj dealloc]

Answer

Correct Answer: [obj release]

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

261. How can you declare a method, that can be set as the action to be performed on various events?

- (IBAction) action:(id) sender;

-(SEL) action:(id) event;

-(selector) action:(id) sender;

Answer

Correct Answer: - (IBAction) action:(id) sender;

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

262. What happens when you call retain on an object?

It is released from memory

It is permanently stored in memory

You increase its retain count by 1

It will stay in memory until the app closes

Answer

Correct Answer: You increase its retain count by 1

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

263. Developers are allowed to call [super dealloc] in ARC.

FALSE

TRUE

Answer

Correct Answer: FALSE

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

264. What is the difference between methods that begin with + and -?

+ methods are public, - methods are private

Instance methods begin with - class level methods begin with +

+ methods are inheritable, - methods are not

Answer

Correct Answer: Instance methods begin with - class level methods begin with +

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

265. What is the Allocations instrument used for?

Allows you to view your variable values

A debugging tool that frees up memory

Recording information from a single process about memory allocation

Answer

Correct Answer: Recording information from a single process about memory allocation

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

266. What is a dependency in NSOperationQueue?

A dependency is a way to have an operation wait to be performed until the dependencies have been fulfilled/executed

A dependency sets the variables of the NSOperationQueue

A dependency is the alloc/init method of the NSOperationQueue

Answer

Correct Answer: A dependency is a way to have an operation wait to be performed until the dependencies have been fulfilled/executed

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

267. True or False? You can compare two strings by (string1 == string2)

False

True

Answer

Correct Answer: False

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

Objective C MCQs | Topic-wise

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Basic Objective C MCQ

1. What is wrong with this line of code? int temp = 1==1;

2. You are worried about threaded access to a property and possible collision in writing. What directive should you use on the property?

3. What is significant about this function declaration? -(void)testFunc:(NSString**)str;

4. Dot notation can be used for _?

5. What's the difference between an array and a set?

6. What is this a declaration of? int(^foo)(int);

7. What are categories used for?

8. If you want to store a small amount of information (e.g., user settings), whats the best, built-in way to go?

9. What is an enums base type for the code below? typedef enum { Foo1, Foo2} Foo;

10. Structs can have _?

11. What is different about this function? +(void)doSomething;

12. What best describes class inheritance in Objective-C?

13. What does ARC stand for?

14. What's wrong with this code?float x = 5.;

15. What is foo? -(float)foo;

16. What is the key difference between NSDictionary and NSMutableDictionary?

17. Property defaults include _?

18. For permanent storage of some data Apple provides:

19. To display some web page, Apple provides a predefined class called:

20. What will be printed on screen after running the following code?int main(){ int a = 5; float c = .5f printf("%.2f", a / c); return 0;}

21. What’s the hierarchy of UITextView class until NSObject?

22. Which of the following is a valid property name of the NSException class?

23. If you need to raise a new exception, you will use:

24. Which of these classes are collections?

25. To create an animation, which starts slowly, but then accelerates as it progresses, you will use:

26. Which of the following is a valid generics type definition?

27. Which of the following is a valid attribute for a property declared in protocol?

28. Which of the following is true?

29. Which of the following is a valid property name of the NSError class?

30. Which of the following is an animatable property of a CALayer object?

31. A proper implementation of “dealloc” method in your custom class must include:

32. Which statement contains a valid code for adding a method, which is not necessary to implement within a class which will conform to the protocol?

33. Which is a correct statement for declaring a new category for UIColor class?

34. When deleting a CoreData NSManagedObject, you can specify to also delete its properties from the database, by setting a rule called:

35. Right after an exception occurs, your program executes the code from the:

36. Which statement about protocols is true?

37. Which of the following is NOT a predefined exception class name?

38. If there was no “@catch” block specified for handling exceptions, what will happen then?

39. Which is a correct statement to declare a new protocol?

40. What is the correct code to include C “Header.h” header in Objective-C “.m” source file?

41. Which of the following is a correct name of memory management method?

42. Which of the following are valid property annotations?

43. Which of the following is true?

44. If a is an integer, the expression !a (...)?

45. As categories can't have instance variables, what class could you use to implement a full class only with categories

46. Using object-oriented programming the object that sends a message

47. All of the methods in a (...) annotated with @required must be implemented.

48. When an object's retainCount reaches 0, which message is automatically sent to that Object?

50. Considering the following Objective-C code, which of the following statements is correct ? // function declaration intfunc(); int main() { // function call inti = func(); } // function definition intfunc() { return 0; }

51. Which of the following is a correct sample of block implementation in Objective-C?

52. It's possible to add a (...) to the standard NSString class, for example, to extend its functionality.

53. Which of the following is NOT correct to state about Objective-C language ?

54. In Objective-C, if I call performSelector:withObject:afterDelay: – is the object retained ?

55. Considering best practices of memory management in Objective-C, is it correct to say that the delegate is never retained ?

56. #import <Foundation/Foundation.h>int main() { inti = 17; char c = 'c'; /* ascii value is 99 */ int sum; sum = i + c; NSLog(@"sum : %d\n", sum ); return 0; } When the above code is compiled and executed, it produces the following result:

57. The following Objective-C code defines ... @interface Fraction (MathOps) ... @end

58. In which of the following situations you would NOT use void types?

59. Which of the following is NOT correct about Protocols ?

60. The Objective-C code ... @interface MyClass : NSObject<Sample> ... @end

61. Considering the following Objective-C code, what will get printed: #import <Foundation/Foundation.h>int main() { int sum = 17, count = 5; CGFloat mean; mean = (CGFloat) sum / count; NSLog(@"mean : %f", mean ); return 0; }

62. Consider below declaration of Song object and tell proper way to call name property? import @interface Song:NSObject { NSString *name; NSString *artist; } (NSString *) name; (NSString *) artist; @ end

63. What is the best way to convert NSNumber into NSString?

64. Name a property attribute that synthesizes accessors that are not thread safe?

65. Where does Objective C store objects, Heap or stack?

66. Look at below code and tell correct output? import static int count; intcnt; for (inti = 0; i<100; i++) { count++; cnt++; } NSLog(@"count=%d cnt=%d\n", count, cnt);

67. What is a local variable that has no default initial value and does not retain its value through method calls?

68. Can you call C++ code from the Objective-C environment?

69. Which of the following is a Singleton?

70. Look at below code and provide the reference counter value after it executes: Object *anObj = [[Object alloc] init]; [anObj retain]; [anObj release]; [anObj release];

71. What will be the output of following code? BOOL isBool = YES; NSLog(@"%d", isBool);

72. Please pick the most suitable difference between alloc and dealloc?

73. An object id with a value of 0?

74. How do you search an object in an object array?

75. Property attribute that synthesizes only a getter for the property?

76. Which is the most proper answer to load plist file contents into an array?

77. Which of the following contain an INCORRECT way to declare and initialize an array ?

78. In Objective-C, sometime, you may find that you wish to extend an existing class by adding behavior that is useful only in certain situations. In order to add such extension to existing classes, Objective-C provides ...

79. The (...) is an Objective-C directive, which is also used to define the aliases for various data types similar to (...). But (...) is limited to giving symbolic names to types only, whereas (...) can be used to define alias for values as well, like you can define 1 as ONE, etc.

80. Which of the following contain an INCORRECT concept regarding Objective-C programming ?

20.
What will be printed on screen after running the following code?
int main()
{
int a = 5;
float c = .5f
printf("%.2f", a / c);
return 0;
}

46.

Using object-oriented programming the object that sends a message

47.
All of the methods in a (...) annotated with @required must be implemented.

48.
When an object's retainCount reaches 0, which message is automatically sent to that Object?

50.
Considering the following Objective-C code, which of the following statements is correct ?
// function declaration intfunc(); int main() { // function call inti = func(); } // function definition intfunc() { return 0; }

51.
Which of the following is a correct sample of block implementation in Objective-C?

52.
It's possible to add a (...) to the standard NSString class, for example, to extend its functionality.

53.
Which of the following is NOT correct to state about Objective-C language ?

54.
In Objective-C, if I call performSelector:withObject:afterDelay: – is the object retained ?

55.
Considering best practices of memory management in Objective-C, is it correct to say that the delegate is never retained ?

56.
#import <Foundation/Foundation.h>int main() { inti = 17; char c = 'c'; /* ascii value is 99 */ int sum; sum = i + c; NSLog(@"sum : %d\n", sum ); return 0; }
When the above code is compiled and executed, it produces the following result:

57.
The following Objective-C code defines
... @interface Fraction (MathOps) ... @end

58.
In which of the following situations you would NOT use void types?

59.
Which of the following is NOT correct about Protocols ?

60.
The Objective-C code ... @interface MyClass : NSObject<Sample> ... @end

61.
Considering the following Objective-C code, what will get printed:
#import <Foundation/Foundation.h>int main()
{ int sum = 17, count = 5; CGFloat mean; mean = (CGFloat) sum / count; NSLog(@"mean : %f", mean ); return 0; }

62.
Consider below declaration of Song object and tell proper way to call name property?
import @interface Song:NSObject { NSString name; NSString artist; } (NSString ) name; (NSString ) artist; @ end

63.
What is the best way to convert NSNumber into NSString?

64.
Name a property attribute that synthesizes accessors that are not thread safe?

65.
Where does Objective C store objects, Heap or stack?

66.
Look at below code and tell correct output?
import static int count; intcnt; for (inti = 0; i<100; i++) { count++; cnt++; } NSLog(@"count=%d cnt=%d\n", count, cnt);

67.
What is a local variable that has no default initial value and does not retain its value through method calls?

68.
Can you call C++ code from the Objective-C environment?

69.
Which of the following is a Singleton?

70.
Look at below code and provide the reference counter value after it executes:
Object *anObj = [[Object alloc] init]; [anObj retain]; [anObj release]; [anObj release];

71.
What will be the output of following code?
BOOL isBool = YES; NSLog(@"%d", isBool);

72.
Please pick the most suitable difference between alloc and dealloc?

73.
An object id with a value of 0?

74.
How do you search an object in an object array?

75.
Property attribute that synthesizes only a getter for the property?

76.
Which is the most proper answer to load plist file contents into an array?

77.
Which of the following contain an INCORRECT way to declare and initialize an array ?

78.
In Objective-C, sometime, you may find that you wish to extend an existing class by adding behavior that is useful only in certain situations. In order to add such extension to existing classes, Objective-C provides ...

79.
The (...) is an Objective-C directive, which is also used to define the aliases for various data types similar to (...). But (...) is limited to giving symbolic names to types only, whereas (...) can be used to define alias for values as well, like you can define 1 as ONE, etc.

80.
Which of the following contain an INCORRECT concept regarding Objective-C programming ?

86.
Which of the following is the base class of all objects in Objective-c ?

87.
Objective-C provides a range of methods to work with NSNumber. Which of the following methods creates and returns an NSNumber object containing a given value, treating it as an NSInteger.

88.
While calling a function by reference, it will copy the actual value of an argument into the formal parameter of the function. In this case, changes made to the parameter inside the function have no effect on the argument. Is the statement above True ?

89.
Objective-C is a general-purpose, object-oriented programming language that adds Smalltalk-style messaging to the (...) programming language. This is the main programming language used by Apple for the OS X and iOS operating systems and their respective APIs, Cocoa and Cocoa Touch.

90.
What happens when the following code executes?
Ball *ball = [[[[Ball alloc] init] autorelease] autorelease];

91.
Which of the following is correct (legal) floating-point literal ?

92.
In Objective-C, a derived class can access all the private members of its base class if it's defined in the interface class, but it cannot access private members that are defined in the implementation file. Is the statement above correct ?

94.
The (...) method can be used to see if an object belongs to a class that implements a particular protocol.

95.
(...) is an abstractClass which represents a stream of data. They are used in Archiving and Unarchiving objects. (...) objects are usually used in a method that is being implemented so that the class conforms to the protocol.

99.
Which of the following is not a property of NSError class?

101.
If you start a class definition that conforms to a specified (...), you will not need to relist all the methods you will implement for that protocol in the @interface section.

103.
What's the hierarchy of UIButton until NSObject ?

104.
Which of the following contains the INCORRECT definition of a Predefined Macro ?

105.
In (...), the system uses the same reference counting system as (...), but it inserts the appropriate memory management method calls for us at compile-time.

106.
Which of the following contains the INCORRECT definition of a preprocessor directive ?

107.
While calling a function by reference, it will copy the address of an argument into the formal parameter. Inside the function, the address is used to access the actual argument used in the call. This means that changes made to the parameter affect the argument. Is the statement above True ?

108.
Which of the following contains the INCORRECT definition of a bitwise operator ?

109.
What is category in Objective-C?

110.
What is the difference between #import and #include?

111.
Where is a MKAnnotationView used?

112.
Which is the most proper answer about the difference between nil and NULL?

113.
The property attribute that causes the setter to store a strong reference to the assigned value is called:

114.
The part of an Objective-C class specification that declares its public interface which includes its superclass name & instances variables and public-method prototypes is called:

115.
What is the difference between the unsigned int and the NSUInteger?

116.
Look at below code and tell which is correct.
(id) init { if ( self == [super init] ) { [self setCaption:@"Default Caption"]; } return self; }

117.
Look at below code and tell what the problem could be:
NSNumber value1 = [[NSNumberalloc] initWithFloat:8.15]; NSNumber value2 = [NSNumber numberWithFloat:8.29]; … … … [value1 release]; [value2 release];

118.
What is the name of the root class in Objective-C?

119.
Two additional foundational building blocks of Objective-C distinct from data and procedure type foundations: _____ and Categories/Extensions?

120.
What is a class object?

121.
How do you free an object?

122.
What is the difference between the unsigned int and the NSUInteger?

123.
What can you do with categories?

124.
What can be linked to an Obj-C program without any particular process?

125.
What is an IMP?

126.
Which of the following is incorrect?

127.
Protocols are like classes; they can inherit

128.
Which of the following declares a protocol?

129.
How do you include the root “Object” class?

130.
What is a protocol?

131.
What can be used as Object instance variables?

132.
What is a @finally block?

133.
How do you throw an exception?

134.
What’s the difference between copy and deepCopy?

135.
Can you send messages to nil?

136.
What is the isa variable in objects?