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Basic C# MCQ

1. When you copy data from a file on a storage device into ram, you are ____ from the file.

Uploading

Writing

Outputing

Reading

Answer

Correct Answer: Reading

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2. A(n) ____ is client software that displays web page elements and handles links between pages.

Explorer

Manager

Browser

Navigator

Answer

Correct Answer: Browser

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3. What is true about thread multitasking?

Thread multitasking allows code to be executed concurrently

Thread multitasking allows code to be executed only when handling a user event.

Thread multitasking blocks code from being executed simultaneously to guard memory.

Thread multitasking adds single-threaded code blocks together.

Answer

Correct Answer: Thread multitasking allows code to be executed concurrently

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4. When can anonymous types be created?

At compile time

After runtime

At runtime

After compile time

Answer

Correct Answer: At compile time

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5. Do you need to declare an out variable before you use it?

No, you can declare it the parameter list.

Out variables are no longer part of C#.

You must declare it if it is a primitive type.

Yes.

Answer

Correct Answer: No, you can declare it the parameter list.

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6. How do you indicate that a string might be null?

A string cannot be nullable.

String? myVariable

String myVariable = null

String(null) myVariable

Answer

Correct Answer: String? myVariable

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7. What is true about virtual methods?

Overriding virtual methods in a derived class is mandatory.

Overriding virtual methods in a derived class is not possible.

Virtual methods always need a default implementation.

Virtual methods cannot have default implementation.

Answer

Correct Answer: Virtual methods always need a default implementation.

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8. Which code snippet correctly declares a variable named userId with a public get and private set?

Public int userID ;

Public int userID [get, private set];

Public int userID { get; private set; }

Public int userID = { public get, private set };

Answer

Correct Answer: Public int userID { get; private set; }

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9. What is the difference between the break and continue keywords?

The break keyword is used to break out of multiple iteration statements, while continue can only break out of code blocks that have single iterations.

The break keyword literally breaks out of a control flow statement, while continue ignores the rest of the control statement or iteration and starts the next one.

The break keyword literally breaks out of the current control flow code and stops it dead, while continue keeps executing the code after an exception is thrown.

The break keyword jumps out of an iteration and then proceeds with the rest of the control flow code, while continue stops the executing code dead.

Answer

Correct Answer: The break keyword literally breaks out of a control flow statement, while continue ignores the rest of the control statement or iteration and starts the next one.

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10. What is the main difference between a value type and a reference type?

A value type can be any primitive type, while reference types must be type-agnostic.

A value type refers to another value, while a reference type refers to a value in memory.

A value type stores an actual value, while a reference type is a pointer to a value.

A value type is available only at runtime, while a reference type is available only at compile time.

Answer

Correct Answer: A value type stores an actual value, while a reference type is a pointer to a value.

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11. How would you write an enum variable called AppState with values for Offline, Loading, and Ready?

Enum AppState = [Offline, Loading, Ready]

Enum AppState {

Enum AppState = {Offline, Loading, Ready}

Enum AppState {Offline, Loading, Ready}

Answer

Correct Answer: Enum AppState {Offline, Loading, Ready}

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12. Which code snippet correctly declares a custom exception named InvalidResponse?

Struct InvalidResponse: Exception {}

Class InvalidResponse: Exception {}

Public Exception InvalidResponse = new Exception ();

Public Exception InvalidResponse () -> Exception;

Answer

Correct Answer: Class InvalidResponse: Exception {}

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13. Your application has a value type called username that needs to be able to accept null values, but this is generating compile-time errors. How would you fix this in code?

Null username = null;

String? username = null;

Type? username = null;

Optional username = null;

Answer

Correct Answer: String? username = null;

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14. What is the difference between finally and finalize blocks?

The finally block is called during the execution of a try and catch block, while the finalize method is called after garbage collection.

The finally block is called after the execution of a try and catch block, while the finalize method is called just before garbage collection.

The finalize block is called before the execution of a try and catch block, while the finally method is called just before garbage collection.

The finalize block is called during the execution of a try and catch block, while the finally method is called after garbage collection.

Answer

Correct Answer: The finally block is called after the execution of a try and catch block, while the finalize method is called just before garbage collection.

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15. What are the four keywords associated with exception handling in C#?

Try, catch, valid, invalid

Try, valid, finally, throw

Try, catch, finally, throw

Finally, throw, valid, invalid

Answer

Correct Answer: Try, catch, finally, throw

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16. What is a delegate

A variable that holds a reference to a value type and its content

A specific value type that can be used only in callback methods

A type that holds a reference to a method with a particular parameter list and return type

A custom variable type that can be used in abstract classes

Answer

Correct Answer: A type that holds a reference to a method with a particular parameter list and return type

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17. When an object in C# is serialized, what is it converted to?

XML

JSON

Byte stream

Value stream

Answer

Correct Answer: Byte stream

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18. What is the most accurate description of a regular expression?

A regular expressions allows a variable to be passed by reference

A regular expression allows a class to conform to the Equatable protocol

A regular expression is a C# tool used to parse HTML

A regular expression is a special text string for describing a search pattern

Answer

Correct Answer: A regular expression is a special text string for describing a search pattern

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19. What is a thread pool?

A collection of synchronous methods created during initialization that cannot be reused

A collection of threads created during initialization that can be reused

A collection of threads only recognized at compile time that can be reused

A collection of asynchronous methods created at compile time that cannot be reused

Answer

Correct Answer: A collection of threads created during initialization that can be reused

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20. What function do namespaces perform?

Namespaces calculate code coverage at runtime.

Namespaces compile application code together at compile time.

Namespaces group code together into a single repository.

Namespaces separate code into groupings, control access, and void naming collisions.

Answer

Correct Answer: Namespaces separate code into groupings, control access, and void naming collisions.

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21. How are C# classses limited?

They do not support multiple inheritance.

They support multiple inheritance.

They can have only a set number of properties.

They can have only a set number of methods.

Answer

Correct Answer: They do not support multiple inheritance.

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22. What method correctly extends the string class?

Public static string IsvalidName(this string i, string value) {}

Public static void IsvalidName(this string i, string value) {}

Public string IsvalidName(this string i, string value) {}

Public void IsvalidName(this string i, string value) {}

Answer

Correct Answer: Public static string IsvalidName(this string i, string value) {}

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23. When will the code inside finally block be executed in a try-catch statement?

If there is an error, it won't execute at all

Between the try and catch blocks

After the try and catch blocks

When the finally block overrides the catch block and executes in its place

Answer

Correct Answer: After the try and catch blocks

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24. What is the correct way to write an event named apiResult based on a delegate named ResultCallback?

Public void event ResultCallback apiResult;

Public event ResultCallback(() -> apiResult);

Public event void ResultCallback

Public event ResultCallback apiResult;

Answer

Correct Answer: Public event ResultCallback apiResult;

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25. What is the difference between a static and non-static method?

Non-static methods always need to have a void return type

Non-static methods do not have access to static member variables

Static methods do not have to instantiate an instance of the class to call the method

Static methods always have to be public

Answer

Correct Answer: Static methods do not have to instantiate an instance of the class to call the method

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26. How would you write a delegate named ResultCallback with an int parameter named responseCode?

Public delegate ResultCallback(int responseCode);

Public delegate void ResultCallback<(int) responseCode>;

Public void delegate ResultCallback;

Public delegate void ResultCallback(int responseCode);

Answer

Correct Answer: Public delegate void ResultCallback(int responseCode);

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27. How would you serialize this class? public class User {}

Mark the User class with the DeserializableAttribute.

Declare the class as public serializable class User {}.

Mark the User class with the SerializableAttribute attribute.

Declare the class as private serializable class User {}.

Answer

Correct Answer: Mark the User class with the SerializableAttribute attribute.

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28. Which characteristic prevents this code from compiling? public int age="28"

Type safety

Single inheritance

Dependency injection

Multiple inheritance

Answer

Correct Answer: Type safety

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29. What is the difference between non-static and static classes?

Non-static classes need to be initialized before use, while static classes do not

Non-static classes are accessible only from an interface while static classes are accessible from anywhere

Non-static classes need to initialize all class members at runtime, while static classes do not

Non-static classes do not need to be initialized while static classes do

Answer

Correct Answer: Non-static classes need to be initialized before use, while static classes do not

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30. What is the correct syntax for a new generic list of strings named contacts? (similar to Q26)

Var contacts = new List();

Var contacts = new List(string);

Public List contacts = new List();

Public List(string names) contacts = new List(string names);

Answer

Correct Answer: Var contacts = new List();

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31. How would you declare a sealed class named User?

Public class User {}

Abstract User {}

Sealed class User {}

Private sealed class User {}

Answer

Correct Answer: Sealed class User {}

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32. When would you use generics in your code?

To increase code performance

All of these answers

When code reuse is a priority

When type safety is important

Answer

Correct Answer: All of these answers

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33. Why would you use a class field in C#

To define behaviours of the class

To hold information and data contained in the class object

To communicate between classes and object

To store the class definition value

Answer

Correct Answer: To hold information and data contained in the class object

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34. What is most accurate description of a regular expression?

A regular expression is a C# tool used to parse HTML

A regular expression is a special text string for describing a search patters.

A regular expression allows a variable to be passed by reference.

A regular expression allows a class to conform to the Equatable protocol.

Answer

Correct Answer: A regular expression is a special text string for describing a search patters.

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35. You're dealing with multiple assemblies in your program, but are worried about memory allocation. At what point in the program life cycle are assemblies loaded into memory?

At runtime

At compile time

Only when required

Only when programmatically loaded

Answer

Correct Answer: Only when required

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36. What character would you use to start a regular expression pattern at a word boundary?

Answer

Correct Answer: \b

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37. Given this enumeration, how would you access the integer-type value of 'AppState.Loading'? enum AppState { OffLine, Loading, Ready }

String currentState = (string)AppState.Loading;

String currentState = AppState.Loading.integralVal;

Int currentState = AppState.Loading.rawValue;

Int currentState = (int)AppState.Loading;

Answer

Correct Answer: Int currentState = (int)AppState.Loading;

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38. What kind of values can arrays store?

Unordered collections of numerc values

Key-value pairs of any C# supported type

Class and struct instances

Multiple variables, or collections, of the same type

Answer

Correct Answer: Multiple variables, or collections, of the same type

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39. What are C# events?

System actions that communicate directly with the compiler at runtime

Actions that execute when the code compiles, generating logs and test output

Actions that generate notifications, which are sent to their registered listeners

User-only methods that send data to the application's back end

Answer

Correct Answer: Actions that generate notifications, which are sent to their registered listeners

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40. When an asynchronous method is executed, the code runs but nothing happens other than a compiler warning. What is most likely causing the method to not return anything?

The return yield statement is missing at the end of the method.

The method is missing an await keyword in its body.

The wait keyword is missing from the end of the method.

The yield keyword is missing from the method.

Answer

Correct Answer: The method is missing an await keyword in its body.

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41. What is the difference between throw exceptions and throw clauses?

Throw clauses fire only at runtime, while throw exceptions can fire at any time.

Throw exceptions overwrite the stack trace, while throw clauses retain the stack information.

Throw clauses overwrite the stack trace, while throw exceptions retain the stack information.

Throw exceptions fire only at runtime, while throw clauses can fire during compile time.

Answer

Correct Answer: Throw exceptions overwrite the stack trace, while throw clauses retain the stack information.

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42. What is the correct syntax for a new generic list of strings named contacts?

Public List contacts = new List();

Public List(string names) contacts = new List(string names)();

Var contacts = new List();

Var contacts = new List(string);

Answer

Correct Answer: Var contacts = new List();

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43. What it the main purpose of LINQ?

To delete duplicate data

To bind namespaces and assemblies

To query and transform data

To connect assemblies

Answer

Correct Answer: To query and transform data

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44. What does operator overloading allow you to do?

Hide built-in operatores when necessary

Add methods to be interpreted by the compiler at runtime

Define how enums and other primitive value types work within the rest of the application

Define custom functionality for common operators like addition and equality

Answer

Correct Answer: Define custom functionality for common operators like addition and equality

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45. Which choice represents a class that inherits behavior from a base class?

A second base class

A revised class

A derived class

A parent class

Answer

Correct Answer: A derived class

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46. When using a thread pool what happens to a given thread after it finishes its task?

The thread is destroyed and memory is freed up.

The thread runs in loop until the next assignment.

The thread goes inactive in the background and waits for garbage collection.

The thread returns to the pool for reuse.

Answer

Correct Answer: The thread returns to the pool for reuse.

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47. What is an abstract class?

A class that is denoted by the class keyword (can be seen and used by any other class in the system--thus it is by default public)

Something denoted by the abstract keyword and used system wide; if you want any program to create an object of a class you use the abstract class

A class that is denoted by the virtual keyword

A class that can be used only as base class

Answer

Correct Answer: A class that can be used only as base class

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48. How would you write code for an integer property called Age with a getter and setter?

Public int Age { get - set }

Public int Age: get set;

Public int Age (get, set );

Public int Age { get; set; }

Answer

Correct Answer: Public int Age { get; set; }

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49. How do you make a method in an abstract class overridable?

Make it public

Make it static

Make it private

Make it virtual

Answer

Correct Answer: Make it virtual

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50. What is the correct formatting for single line and multiline comments?

// - Single Line / - Multiline

// Multiline /_ Single Line _/

//* Multiline / Single Line

// Single Line /_ Multiline _/

Answer

Correct Answer: // Single Line /_ Multiline _/

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51. Lambda expressions are often used in tandem with which of the following?

Namespaces

LINQ

Type Aliasing

Assemblies

Answer

Correct Answer: LINQ

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52. What will be returned when this method is executed? public void userInput(string charParamters) { }

Nothing

A Boolean

A string variable

An integer

Answer

Correct Answer: Nothing

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53. Which code snippet declares an anonymous type named userData?

var<T> userData = new <T> { name = "John", age = 32 };

var userData = new { name = "John", age = 32 };

AType userData = new AType { name = "John", age = 32 };

Anonymous userData = new Anonymous { name = "John", age = 32 };

Answer

Correct Answer: var userData = new { name = "John", age = 32 };

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54. What is an object in C#?

A class or struct, including its variables and functions

A primitive data type that can be created only at compile time

A value type that can be used only with an abstract class

An instance of a class or struct that includes fields, properties, and/or methods

Answer

Correct Answer: An instance of a class or struct that includes fields, properties, and/or methods

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55. How does the async keyword work?

It allows access to asynchronous methods in the C# API

It allows thread pooling and synchronous processes in static classes.

It allows the await keyword to be used in a method

It allows access to synchronous methods in the C# API

Answer

Correct Answer: It allows the await keyword to be used in a method

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56. Which choice best describes a deadlock situation?

When you try to instantiate two objects at the same time in the same class or struct

When you are trying to execute an action after a user event is registered

When simultaneous instructions are waiting on each other to finish before executing

When you try to execute a series of events simultaneously on multiple threads

Answer

Correct Answer: When simultaneous instructions are waiting on each other to finish before executing

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57. What is the difference between a.Equals(b) and a == b?

The .Equals method compares reference identities while the == compares contents.

The .Equals method compares primitive values while == compares all values.

The .Equals method compares contents while == compares references reference identity.

The .Equals method compares reference type while == compares primitive value types.

Answer

Correct Answer: The .Equals method compares contents while == compares references reference identity.

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58. When would you use a Dictionary rather that an Array type in your application?

When you need a jagged collection structure

When you need to store values of the same type

When you need to store key-value pairs rather than single values

When you need an ordered, searchable list

Answer

Correct Answer: When you need to store key-value pairs rather than single values

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59. What is the difference between an anonymous type and a regular data type?

Anonymous types don't have type names

Anonymous types can only be static

Anonymous types can be used only in struts

Anonymous types don't work with LINQ.

Answer

Correct Answer: Anonymous types don't have type names

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60. How could you retrieve information about a class, as well as create an instance at runtime?

Reflection

Serialization

Abstraction

Dependency injection

Answer

Correct Answer: Reflection

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61. What is the difference between the ref and out keywords?

Variables passed to out specify that the parameter is an output parameter, while ref specifies that a variable may be passed to a function without being initialized.

Variables passed to ref can be passed to a function without being initialized, while out specifies that the value is a reference value that can be changed inside the calling method.

Variables passed to out can be passed to a function without being initialized, while ref specifies that the value is a reference value that can be changed inside the calling method.

Variables passed to ref specify that the parameter is an output parameter, while out specifies that a variable may be passed to a function without being initialized.

Answer

Correct Answer: Variables passed to out can be passed to a function without being initialized, while ref specifies that the value is a reference value that can be changed inside the calling method.

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62. Which choice best defines C#'s asynchronous programming model?

Reactive

Inherited callback

Task-based

Callback-based

Answer

Correct Answer: Task-based

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63. Which statement is true of delegates?

Delegates are not supported in the current version of C#

They cannot be used as callbacks.

Only variables can be passed to delegates as parameters.

They can be chained together.

Answer

Correct Answer: They can be chained together.

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64. In which of these situations are interfaces better than abstract classes?

When you need to define an object type's characteristics, use an interface. When you need to define an object type's capabilities, use an abstract class.

Interfaces are a legacy of older versions of C#, and are interchangeable with the newer abstract class feature.

When you need a list of capabilities and data that are classes-agnostic, use an interface. When you need a certain object type to share characteristics, use an abstract class.

You should use both an interface and an abstract class when defining any complex object.

Answer

Correct Answer: When you need a list of capabilities and data that are classes-agnostic, use an interface. When you need a certain object type to share characteristics, use an abstract class.

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65. A(n) ____ is associated with every running program.

66. A(n) ____ constructor will never take any parameters.

Object

Initializ er

Array

Default

Answer

Correct Answer: Default

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67. An array is a(n) ____ of values in computer memory.

List

Accumulation

Set

Record

Answer

Correct Answer: List

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68. The ____ class provides the definitions for gui objects.

Control

Object

Widget

Gadget

Answer

Correct Answer: Control

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69. A(n) ____ is another name for a subscript.

Pointer

Sequence

Index

Place holder

Answer

Correct Answer: Index

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70. A variable that holds the accumulated result of a sum is called a(n) __________.

Grand total.

Total.

Running total.

Accumulator

Answer

Correct Answer: Accumulator

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71. A method’s name and a list of argument types together are its ____.

Profile

Header

Interface

Signature

Answer

Correct Answer: Signature

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72. The ____ class access modifier means that access to the class is not limited.

Internal

Protected

Abstract

Visible

Answer

Correct Answer: Internal

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73. A string variable can be declared as an array with elements that are of __________ type.

Subscript

Matrix

Character

Flag

Answer

Correct Answer: Character

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74. The starting point of a c# program is the _____ method.

Main

Start

Open

None of the above

Answer

Correct Answer: Main

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75. The ____ control allows you to retrieve date information.

Calendar

MonthCalendar

DateCalendar

CalendarPicker

Answer

Correct Answer: MonthCalendar

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76. you can use the ____ method to accept user input from the keyboard.

ReadLine()

NextLine()

Input()

Next()

Answer

Correct Answer: ReadLine()

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77. Predefined types such as int, double, and char are ____ types.

Public

Accessors

Private

Value

Answer

Correct Answer: Value

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78. Object attributes are often called ____ to help distinguish them from other variables you might use

Constructors

Instances

Fields

Records

Answer

Correct Answer: Fields

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79. In c#, parameters can be mandatory or ____.

Objects

Optional

Values

Positional

Answer

Correct Answer: Optional

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80. If you do not provide an access specifier for a class field, its access is ____ by default.

Private

Public

Protected

Answer

Correct Answer: Private

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81. An example of a floating point data type is ____.

False

True

Char

Double

Answer

Correct Answer: Double

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82. A generic class is defined ____ on the class definition line.

By inserting an identifier between left and right brackets

By inserting the word generic

By inserting an identifier between left and right parentheses

By removing the type

Answer

Correct Answer: By inserting an identifier between left and right parentheses

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83. Which of the following components of the .Net framework provide an extensible set of classes that can be used by any .Net compliant programming language?

Java Virtual Machine

Python Virtual Machine

Common Language Runtime

.Net class libraries

Common Language Infrastructure

Component Object Model

Answer

Correct Answer: .Net class libraries

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84.
Consider the following C# code. What would be the value of d?
int? a = 10;
int? b = 11;
int? c = 12;
a = null;
int? d = a ?? b ?? c;

None of the above

Answer

Correct Answer:

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85.
What is the output of the following code?

static void Main(string[] args)
{
int a = 5;
if (Convert.ToBoolean((.002f) -(0.1f)))
Console.WriteLine("Hello");
else if (a == 5)
Console.WriteLine("World");
else
Console.WriteLine("Bye");
Console.ReadLine();
}

World

Hello

Bye

Warning: Unreachable code

Answer

Correct Answer: Hello

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86. At what times can a readonly field of a class be initialized? (Choose all that apply)

At the time of field's declaration

At the time of instantiating the class, in any constructor of the class

Anywhere but only once in a Program

All of the above

Answer

Correct Answer: At the time of field's declaration
At the time of instantiating the class, in any constructor of the class

Note: This question has more than 1 correct answers

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87. Which of the following benefits do we get on running managed code under CLR? 1. Type safety of the code running under CLR is assured. 2. It is ensured that an application would not access the memory that it is not authorized to access. 3. It launches separate process for every application running under it. 4. The resources are Garbage collected.

Only 1 and 2

Only 2, 3 and 4

Only 1, 2 and 4

4 only.

All of the above

Answer

Correct Answer: All of the above

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88. What is the default type of a number without a decimal in C#?

Long Int

Unsigned Long

Int

Unsigned Int

Answer

Correct Answer: Int

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

89. Which of the following statements is false about virtual and abstract methods?

A virtual method is permitted in a sealed class

An abstract method must be overridden in every non-abstract derived class

An abstract method is permitted only in a class that is also declared abstract

An abstract method is a virtual method with no implementation

Answer

Correct Answer: A virtual method is permitted in a sealed class

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

90. Which of the following are not ordered collection classes? (choose all that apply)

Map

Stack

Queue

BitArray

HashTable

Answer

Correct Answer: Map
BitArray
HashTable

Note: This question has more than 1 correct answers

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

91. Disadvantages of Explicit Conversion are ? (Choose all that apply)

Can result in loss of data.

Is potentially unsafe.

None of the above mentioned.

Answer

Correct Answer: Can result in loss of data.
Is potentially unsafe.

Note: This question has more than 1 correct answers

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

92. Which statement about a String is correct?

A String is created on the stack.

Whether a String is created on the stack or the heap depends on the length of the String.

A String is created on the heap.

A String can be created by using the statement String s1 = new String;

Answer

Correct Answer: A String is created on the heap.

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

93. Choose the incorrect statement among the following about the delegate?

delegates are of reference types

delegates are object oriented

delegates are type safe

None of the above

Answer

Correct Answer: None of the above

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

94. Choose the class from which the namespace ‘System.Type’ is derived:

System.Reflection

System.Reflection.MemberInfo

Both of the above

None of the above

Answer

Correct Answer: System.Reflection.MemberInfo

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

95. Which of the following are jobs not performed by the Garbage Collector? 1. Freeing stack memory. 2. Avoiding memory leakage. 3. Freeing memory occupied by unreferenced objects. 4. Closing unclosed database collections. 5. Closing unclosed files.

1, 2, 3

3, 5

1, 4, 5

3, 4

Answer

Correct Answer: 1, 4, 5

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

96. Choose the method defined by MemberInfo:

GetCustomAttributes()

IsDefined()

GetCustomeAttributesData()

All of the above

Answer

Correct Answer: All of the above

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

97. What is the purpose of the Open XML SDK 2.0?

To do Microsoft Office-related tasks

To do XML-related tasks

To do database-related tasks

None of these

Answer

Correct Answer: To do Microsoft Office-related tasks

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

98. Which is the correct way to find out the number of elements currently present in an ArrayListCollection called arr?

arr.Capacity

arr.Count

arr.MaxIndex

arr.UpperBound

Answer

Correct Answer: arr.Count

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

99. Choose the namespace in which the interface IEnumerable is declared?

System.Collection

System.Collections.Generic

Both 1 and 2

None of the above

Answer

Correct Answer: System.Collections.Generic

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

100.
Which of the following is the correct way to call method Jobs() of the UpWork class given below? class UpWork { public void Jobs(inti, Single j) { Console.Writeline('UpWork'); } }

delegate void del(inti); UpWork u = new UpWork(); d = new del(ref u.Jobs); d(10, 1.1f);

delegate void del(inti, Single j); del d; UpWork u = new UpWork(); d = new del(ref u.Jobs); d(10, 1.1f);

UpWork u = new UpWork(); delegate void d = new del(ref u.Jobs); d(10, 1.1f);

delegate void del(inti, Single j); UpWork u = new UpWork(); del = new del(ref u.Jobs); d(10, 1.1f);

Answer

Correct Answer: delegate void del(inti, Single j); del d; UpWork u = new UpWork(); d = new del(ref u.Jobs); d(10, 1.1f);

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

101. What is true about a sealed class in C#?

A sealed class cannot be inherited by any other class and sealed classes are primarily used to prevent derivation

The source code of a sealed class cannot be decompiled from the assembly

A sealed class does not have any public methods and its operations are sealed

None of the above

Answer

Correct Answer: A sealed class cannot be inherited by any other class and sealed classes are primarily used to prevent derivation

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

102.
What would be the output of following code snippet?
Namespace Outer
{
Using System;
Class Math
{
}
}
Namespace Outer.Inner
{
Class Foo
{
Public static double Bar()
{
Return Math.PI;
}
}
Class program
{
Public static void Main()
{
Console.WriteLine(“Value of PI is; “ + Foo.Bar() .ToString());
}
}
}

It will print the value of PI.

It will give a compile time error.

It will compile properly but give a runtime error.

None of these.

Answer

Correct Answer: It will give a compile time error.

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

103.
Which of the following is the correct way to convert a Byte Array to a Hexadecimal String, and vice versa?

static readonly char[] _hexDigits = "0123456789abcdef".ToCharArray(); public static string ToHexString(this byte[] bytes) { char[] digits = new char[bytes.Length * 2]; for (inti = 0; i<bytes.Length; i++) { int d1, d2; d1 = Math.DivRem(bytes[i], 16, out d2); digits[2 * i] = _hexDigits[d1]; digits[2 * i + 1] = _hexDigits[d2]; } return new string(digits); }

public static byte[] StringToByteArray(String hex) { intNumberChars = hex.Length/2; byte[] bytes = new byte[NumberChars]; StringReadersr = new StringReader(hex); for (inti = 0; i<NumberChars; i++) bytes[i] = Convert.ToByte(new string(new char[2]{(char)sr.Read(), (char)sr.Read()}), 16); sr.Dispose(); return bytes; }

System.Runtime.Remoting.Metadata.W3cXsd2001; public byte[] GetStringToBytes(string value) { SoapHexBinaryshb = SoapHexBinary.Parse(value); return shb.Value; } public string GetBytesToString(byte[] value) { SoapHexBinaryshb = new SoapHexBinary(value); return shb.ToString(); }

String.Join(String.Empty, Array.ConvertAll(bytes, x =>x.ToString("X2")));

Answer

Correct Answer: static readonly char[] _hexDigits = "0123456789abcdef".ToCharArray(); public static string ToHexString(this byte[] bytes) { char[] digits = new char[bytes.Length * 2]; for (inti = 0; i<bytes.Length; i++) { int d1, d2; d1 = Math.DivRem(bytes[i], 16, out d2); digits[2 * i] = _hexDigits[d1]; digits[2 * i + 1] = _hexDigits[d2]; } return new string(digits); }

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

104.
Consider the following code:
class Program {
static void Main(string[] args) {
     float f =
     double d =
     decimal dc = 0;
     PrintDouble(f); // Statement 1
     PrintDouble(d); // Statement 2
     PrintDouble(dc); // Statement 3
}
static private void PrintDouble(double d) {
     Console.WriteLine(d.ToString());
}
}
Which of the following are true?

Statement 1 will generate a compilation error

Statement 2 will generate a compilation error.

Statement 3 will generate a compilation error.

No compilation error will be generated.

Answer

Correct Answer: Statement 3 will generate a compilation error.

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

105.

Which of the following predefined attributes in C# ?

Conditional

Obsolete

Attribaute Usage

All of the above

Answer

Correct Answer: All of the above

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

106.
Where should auto implemented properties be initialized to a Default value?

In the constructor

In the code apart from the constructor

By using reflection

They cannot be initialized

Answer

Correct Answer: In the constructor

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

107.
Select the type argument of an open constructed type.

Gen

Gen<>

Both of the above

None of the mentioned

Answer

Correct Answer: Gen<>

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

108.
Which of the following interfaces are declared in the System.Collections namespace? (Choose all that apply)

ICollection

IComparer

IDictionary

IList

IDictionaryComparer

IEnumerator

IDictionaryEnumerator

IDeviceContext

Answer

Correct Answer: ICollection
IComparer
IDictionary
IList
IEnumerator
IDictionaryEnumerator

Note: This question has more than 1 correct answers

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

109.
Choose the advantages of using generics?

Generics facilitate type safety

Generics facilitate improved performance and reduced code

Generics promote the usage of parameterized types

All of the mentioned

Answer

Correct Answer: All of the mentioned

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

110.
Which statement is correct about an Exception?

It occurs during compilation.

It occurs during linking.

It occurs at run-time.

It occurs during Just-In-Time compilation.

It occurs during loading of the program.

Answer

Correct Answer: It occurs at run-time.

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

111.
Which String method is used to compare two strings?

Compare_To()

Compare()

Copy()

ConCat()

Answer

Correct Answer: Compare()

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

112.
Which of the following is NOT a .NET Exception class?

Exception

StackMemoryException

DivideByZeroException

OutOfMemoryException

InvalidOperationException

Answer

Correct Answer: StackMemoryException

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

113.
Verbatim string literal is better used for ?

Convenience and better readability of strings when string text consist of backlash characters

Used to initialize multi line strings

To embed a quotation mark by using double quotation marks inside a verbatim string

All of the above

Answer

Correct Answer: All of the above

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

114.
Which datatype should be used for storing a simple number like 35 to improve execution speed of a program?

sbyte

short

int

long

Answer

Correct Answer: sbyte

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

115.
Which of the following is not an interface declared in System.Collection namespace?

IDictionaryComparer

IEnumerable

IEnumerator

Icomparer

Answer

Correct Answer: IDictionaryComparer

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

116.
Which operator is used to access member function of a class?

Answer

Correct Answer: .

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

117.
Select the error in the given program : public static void Main() { const int m = 100; int n = 10; const int k = n / 5 * 100 * n ; Console.WriteLine(m * k); Console.ReadLine(); }

‘k’ should not be declared constant.

Expression assigned to ‘k’ should be constant in nature.

Expression (m * k) is invalid.

‘m ‘ is declared in invalid format.

Answer

Correct Answer: Expression assigned to ‘k’ should be constant in nature.

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

118.
Assume 2 columns are named Product and Category. How can they be sorted based on first by category and then by product name?

var sortedProds = _db.Products.Orderby(c => c.Category)

var sortedProds = _db.Products.Orderby(c => c.Category) + ThenBy(n => n.Name)

var sortedProds = _db.Products.Orderby(c => c.Category) . ThenBy(n => n.Name)

All of the mentioned

Answer

Correct Answer: var sortedProds = _db.Products.Orderby(c => c.Category) . ThenBy(n => n.Name)

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

119.
The ‘ref’ keyword can be used as: (Check all that apply)

Static function/subroutine

Static data

Instance function/subroutine

Instance data

Answer

Correct Answer: Static function/subroutine
Instance function/subroutine

Note: This question has more than 1 correct answers

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

120.
In C#.NET, if we do not catch the exception thrown at runtime then which of the following will catch it?

Compiler

CLR

Linker

Loader

Operating system

Answer

Correct Answer: CLR

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

121.
Which feature allows you to obtain information about the use and capabilities of types at runtime?

Runtime type ID

Reflection

Attributes

None of the mentioned

Answer

Correct Answer: Reflection

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

122.
What is the problem with the following function? (The code is supposed to convert a Stream into byte array) public static byte[] ReadFully(Stream input) { using (MemoryStream ms = new MemoryStream()) { input.CopyTo(ms); return ms.ToArray(); } }

It will work only in .NET Framework 4 or above, as the CopyTo function of the memory stream is available only in .NET Framework 4 or later versions.

It will work only in .NET Framework 3.5 or below, as the CopyTo function of the memory stream is available only in .NET Framework 3.5 or earlier versions.

It will work in all versions of the .NET framework.

None of the above

Answer

Correct Answer: It will work only in .NET Framework 4 or above, as the CopyTo function of the memory stream is available only in .NET Framework 4 or later versions.

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

123.
How many Bytes are stored by ‘Long’ Datatype in C# .net?

a) 8

b) 4

c) 2

d) 1

Answer

Correct Answer: a) 8

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

124.
Which of the following statements is true about the .Net framework and DCOM?

.Net framwork uses DCOM for achieving language interoperability.

.Net framework is built on the DCOM technology.

.Net framwork uses DCOM for making transition between managed and unmanaged code.

.Net framwork uses DCOM for creating unamanged applications.

.Net framwork uses DCOM while creating distributed applications.

Answer

Correct Answer: .Net framwork uses DCOM for making transition between managed and unmanaged code.

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

125.
Consider an ArrayList collection that implements the IEnumerable interface. Which of the following statements are true?

The ArrayList class contains an inner class that implements the IEnumberable interface.

An ArrayList Collection cannot be accessed simultaneously by different threads.

The inner class of ArrayList can access ArrayList class's members.

To access members of ArrayList from the inner class, it is necessary to pass ArrayList class's reference to it.

Enumerators of ArrayList Collection can manipulate the array.

Answer

Correct Answer: The ArrayList class contains an inner class that implements the IEnumberable interface.
The inner class of ArrayList can access ArrayList class's members.
To access members of ArrayList from the inner class, it is necessary to pass ArrayList class's reference to it.

Note: This question has more than 1 correct answers

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

126.
Among the given collections which one is I/O index based? (Choose all that apply).

a) ArrayList

b) BitArray

c) Stack

d) Queue

Answer

Correct Answer: a) ArrayList

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

127.
Among the given collections which one is I/O index based? (Check all that apply)

a) ArrayList

b) BitArray

c) Stack

d) Queue

Answer

Correct Answer: a) ArrayList
b) BitArray

Note: This question has more than 1 correct answers

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

128.
Which of the following constitute the .Net framework?

ASP.Net Applications

CLR

MS Office

Framework Class Library

Winform Applications

Windows Services

Python Interpreter

Java Runtime Environment

Answer

Correct Answer: CLR
Framework Class Library

Note: This question has more than 1 correct answers

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

129.
Which of the following keywords is used to manually throw an exception handling?

try

catch

throw

finally

Answer

Correct Answer: throw

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

130.
What is Semaphore?

a) Grant more than one thread access to a shared resource at the same time.

b) Useful when a collection of resources is being synchronized

c) Make use of a counter to control access to a shared resource

d) Only b & c

Answer

Correct Answer: a) Grant more than one thread access to a shared resource at the same time.
b) Useful when a collection of resources is being synchronized
c) Make use of a counter to control access to a shared resource

Note: This question has more than 1 correct answers

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

131.
A generic type with arguments provided, like KeyValuePair, is called?

A constructed type

A derived type

An implemented type

None of the above

Answer

Correct Answer: A constructed type

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

132.
Which of the following statements are correct about a HashTable collection? (Choose all that apply)

a) It is a keyed collection

b) It is a ordered collection

c) It is an indexed collection

d) It implements a IDictionaryEnumerator interface in its inner class

Answer

Correct Answer: a) It is a keyed collection
d) It implements a IDictionaryEnumerator interface in its inner class

Note: This question has more than 1 correct answers

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

133.
Which is the correct way to enumerate an Enum in C#?

foreach (Suit suit in Enum.GetValues(typeof(Suit))) { }

foreach (Suit suit in Enum(typeof(Suit))) { }

foreach (Suit suit in Enum(Suit)) { }

foreach (Suit suit in Enum.GetValues(Suit)) { }

Answer

Correct Answer: foreach (Suit suit in Enum.GetValues(typeof(Suit))) { }

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

134.
Identifier is a name which can be used to identify a , , __?

variable, function, method

class, instance, function

class, variable, function

class, method, function

Answer

Correct Answer: class, variable, function

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

135.
The expression of a lock statement must denote a value of a type known to be a?

reference-type

value-type

None of the above

Answer

Correct Answer: reference-type

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

136.
Which statement is correct about the C#.NET code snippet given below? Stack st = new Stack(); st.Push("Csharp"); st.Push(7.3); st.Push(8); st.Push('b'); st.Push(true);

a) Unsimilar elements like “Csharp”,7.3,8 cannot be stored in the same stack collection.

b) Boolean values can never be stored in Stack collection

c) Perfectly workable code

d) All of the mentioned

Answer

Correct Answer: c) Perfectly workable code

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

137.
What is the difference between const and readonly?

A const is restricted to primitive/value types (the exception being strings).

A const is a compile-time constant where as read-only allows a value to be calculated at run-time.

A const is a compile-time constant whereas read-only allows a value to be calculated at run-time and set in the constructor or field initializer. So, a 'const' is always constant but 'read-only' is read-only once it is assigned.

A const is not Static by default and must have compilation-time value. Read only are evaluated when code execution hits class and must have evaluated value by the time static constructor is done.

Answer

Correct Answer: A const is a compile-time constant whereas read-only allows a value to be calculated at run-time and set in the constructor or field initializer. So, a 'const' is always constant but 'read-only' is read-only once it is assigned.

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

138.
Which of the following properties related to network errors is generated by WebException?

Get

Send

Response

Status

Answer

Correct Answer: Response
Status

Note: This question has more than 1 correct answers

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

139.
What is the output if following code executed? static void Main(string[] args){ String obj = "sample"; String obj1 = "program"; String obj2 = obj; Console.WriteLine(obj + " " + obj1); string s = obj + " " + obj1; Console.WriteLine(s.Length); Console.ReadLine(); }

Sample program

Run time error

Compile time error

Answer

Correct Answer: Sample program

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

140.
Which among the following is the ordered collection class? (Check all that apply)

BitArray

Queue

HashTable

Stack

Answer

Correct Answer: Queue
Stack

Note: This question has more than 1 correct answers

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

141.
Which of the following is an ordered collection class? (choose all that apply)

Map

Stack

Queue

BitArray

HashTable

Answer

Correct Answer: Stack
Queue

Note: This question has more than 1 correct answers

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

142.
What kind of exception is being thrown if Wait(),Pulse() or PulseAll() iscalled from code that is not within synchronized code?

a) System I/O Exception

b) DivideByZero Exception

c) SynchronizationLockException

d) All of the mentioned

Answer

Correct Answer: c) SynchronizationLockException

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

143.
Structures can have methods, , , _____, operator methods, and events?

variables, class, properties

fields, indexers, properties

functions, indexers, properties

class, variables, properties

Answer

Correct Answer: fields, indexers, properties

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

144.
A class consists of two with each interface consisting of , __ and class had no instance data?

interfaces, three, methods

function, two, methods

variable, one, methods

object, three, methods

Answer

Correct Answer: interfaces, three, methods

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

145.
C# has support for strongly-typed function pointers via the keyword?

delegate

variable

class

methods

Answer

Correct Answer: delegate

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

146.
Which of the following keywords must be used to monitor exceptions handling?

try

catch

throw

finally

Answer

Correct Answer: try

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

147.
Choose the namespace in which Expression trees are encapsulated?

a) System.Linq

b) System.Linq.Expressions

c) System.Text

d) System.Collections.Generic

Answer

Correct Answer: b) System.Linq.Expressions

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148.
Which of the following is the correct syntax to group query results using LINQ?

var query = from student in students group student by student.LastName into newGroup orderby newGroup.Key select newGroup;

var query = from student in students groupby student.LastName into newGroup orderby student.LastName select newGroup;

var query = from student in students groupby student.LastName orderby student.LastName select student.LastName

var query = from student in students groupings {student.LastName} into newGroup select newGroup;

Answer

Correct Answer: var query = from student in students group student by student.LastName into newGroup orderby newGroup.Key select newGroup;

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

149.
Which of the following types of LINQ?

LINQ to Objects

LINQ to SQL

LINQ to XML

LINQ to Dataset

All of the above

Answer

Correct Answer: All of the above

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150.
What is the difference between “throw ex” and “throw” in C#?

“throw ex” will preserve the original stack trace info

“throw” will replace the stack trace of the exception with stack trace info of re throw point

“throw ex” will replace the stack trace of the exception with stack trace info of re throw point and “throw” will preserve the original stack trace info

None of the above

Answer

Correct Answer: “throw ex” will replace the stack trace of the exception with stack trace info of re throw point and “throw” will preserve the original stack trace info

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151.
Choose the correct statement about System.Type namespace?

a) Core of the reflection subsystem as it encapsulates a type

b) Consists of many methods and properties that can be used to obtain information about a type at runtime

c) Both of the above

d) Only b

Answer

Correct Answer: c) Both of the above

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152.
Recursion is a process of defining a ___ that calls itself repeatedly in C#?

Interface

Method

Class

Constructors

Answer

Correct Answer: Method

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153.
What are the types of children does object element can have in XAML?

a) Collection Items

b) A value for the content property

c) The value that can be type-converted to the object element

d) None of the above

Answer

Correct Answer: a) Collection Items
b) A value for the content property
c) The value that can be type-converted to the object element

Note: This question has more than 1 correct answers

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154.
Which of the following right syntax for declaration and initialization of data variable?

datatype><var_name>:<Value>;

data type><var_name> = <Value>;

var_name><data type>::<Value>;

var_name> = <value>

Answer

Correct Answer: data type><var_name> = <Value>;

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

155.
Which of the following how you can use retrieve a single row with LINQ?

Public User GetUser (string userName){ DBNameDataContext myDB = new DBNameDataContext ( ) ; User user = myDB. User. Singles ( u, u.UserName => userName ); Return user; }

Public User GetUser (string userName){ DBNameDataContext myDB = new DBNameDataContext ( ) ; User user = myDB. Users. SingleObject ( u, u.UserName => userName ); Return user; }

Public User GetUser (string userName){ DBNameDataContext myDB = new DBNameDataContext ( ) ; User user = myDB. Users. Single ( u, u.UserName => userName ); Return user; }

Public User GetUser (string userName){ DBNameDataContext myDB = new DBNameDataContext ( ) ; User user => myDB. Users. Single ( u, u.UserName = userName ); Return user; }

Answer

Correct Answer: Public User GetUser (string userName){ DBNameDataContext myDB = new DBNameDataContext ( ) ; User user = myDB. Users. Single ( u, u.UserName => userName ); Return user; }

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

156.
Which of the following statements are correct about delegates?

Delegates are reference types.

Delegates are object oriented.

Delegates are type-safe.

Delegates serve the same purpose as function pointers in C and pointers to member function operators in C++.

Only one method can be called using a delegate.

Delegates are secure.

Answer

Correct Answer: Delegates are reference types.
Delegates are object oriented.
Delegates are type-safe.
Delegates serve the same purpose as function pointers in C and pointers to member function operators in C++.
Delegates are secure.

Note: This question has more than 1 correct answers

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

157.
Which of the following statements about deleagtes are UNTRUE?

Delegates are not type-safe.

Delegate is a user-defined type.

Only one method can be bound with one delegate object.

Delegates can be used to implement callback notification.

Delegates permit execution of a method on a secondary thread in an asynchronous manner.

Answer

Correct Answer: Delegates are not type-safe.
Only one method can be bound with one delegate object.

Note: This question has more than 1 correct answers

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

158.
Consider the following delegate declaration,Which of the following are TRUE? delegate void del(int i);

On declaring the delegate, a class called del will get created.

The signature of del must be the same as the signature of the method that we intend to call using it.

The del class will be derived from the MulticastDelegate class.

The method that can be called using del should not be a static method.

The del class will contain a one-argument constructor and an Invoke() method.

Answer

Correct Answer: On declaring the delegate, a class called del will get created.
The del class will be derived from the MulticastDelegate class.
The del class will contain a one-argument constructor and an Invoke() method.

Note: This question has more than 1 correct answers

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159.
DataContext class acts as a bridge between SQL Server database and the _____ to SQL?

Delegate

LINQ

Class

Answer

Correct Answer: LINQ

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

160.
Which of the following code samples will read an integer from a byte[]?

int i; tab = new byte[32]; i = readint(tab,0,3); i = readint(tab,4,7)

byte[] bytes = { 0, 0, 0, 25 }; if (BitConverter.IsLittleEndian) Array.Reverse(bytes); int i = BitConverter.ToInt32(bytes, 0); Console.WriteLine("int: {0}", i);

public class BigEndian : Endian { protected override long FromBytes(byte[] buffer, int startIndex, int len) { long ret = 0; for (int i=0; i < len; i++) { ret = unchecked((ret << 8) | buffer[startIndex+i]); } return ret; } } public class LittleEndian : Endian { protected override long FromBytes(byte[] buffer, int startIndex, int len) { long ret = 0; for (int i=0; i < len; i++) { ret = unchecked((ret << 8) | buffer[startIndex+len-1-i]); } return ret; } }

byte[] data = ...; int startIndex = 0; int value = data[startIndex]; for (int i=1;i<4;i++) { value <<= 8; value |= data[i+startIndex]; }

Answer

Correct Answer: byte[] bytes = { 0, 0, 0, 25 }; if (BitConverter.IsLittleEndian) Array.Reverse(bytes); int i = BitConverter.ToInt32(bytes, 0); Console.WriteLine("int: {0}", i);

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161.
How can extension methods be added to an existing static class?

Using a static wrapper class that implements the same signature, and defers the actual call to the class

Using instance-based extension methods

Using the System.Environment class

Extension methods cannot be added to a static class.

Answer

Correct Answer: Extension methods cannot be added to a static class.

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

162.
Which of the following is not a keyword in C#?

goto

jump

yeild

continue

Answer

Correct Answer: jump

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

163.
Which of the following statements is true about the System.Environment.NewLine property?

It's a string containing "\n" for non-Unix platforms.

It's a string containing "\n" for Unix platforms.

It's a string containing "\r\n" for non-Unix platforms.

It's a string containing "\r\n" for Unix platforms.

Answer

Correct Answer: It's a string containing "\r\n" for non-Unix platforms.

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

164.
What does the following code block define? Check all that apply. class Gen { T ob; }

Generics class declaration

Declaration of variable

A simple class declaration

All of the mentioned

Answer

Correct Answer: Generics class declaration
Declaration of variable

Note: This question has more than 1 correct answers

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165.
Which of the following is a correct way to convert a String to an int in C#?

String s = "456"; int i; i = (int)s;

String s = "456"; int i; i = int.Parse(s);

String s = "456"; int i; i = Int32.Parse(s);

String s = "456"; int i; i = Convert.ToInt32(s);

String s = "456"; int i; i = CInt(s);

Answer

Correct Answer: String s = "456"; int i; i = int.Parse(s);
String s = "456"; int i; i = Int32.Parse(s);
String s = "456"; int i; i = Convert.ToInt32(s);

Note: This question has more than 1 correct answers

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166.
Which of the following is not a valid .NET Framework Attribute?

[DebuggerDisplay]

[Searializable]

[Flags]

[ClassMethod]

Answer

Correct Answer: [ClassMethod]

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167.
What will be the output of the following Main program in a C# console application (Assume required namespaces are included)? private static void TestSwitch(int iValue) { switch (iValue) { case 1: case 2: case 3: case 4: Console.WriteLine("I am less than 5."); break; case 6: case 7: case 8: Console.WriteLine("I am greater than 5."); break; default: Console.WriteLine("I handle rest."); break; } } static void Main(string[] args) { TestSwitch(2); TestSwitch(8); TestSwitch(5); Console.ReadLine(); }

This program will not compile as C# does not allow fall-through in multiple case statements.

I am less than 5. I am greater than 5. I handle rest.

I am less than 5. I handle rest. I am greater than 5.

I am less than 5. I handle rest. I handle rest.

Answer

Correct Answer: I am less than 5. I am greater than 5. I handle rest.

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168.
What is the output of the following code? class Test { static void Main() { string s = @"Joe said\t ""Hello"" to me!"; System.Console.WriteLine(s); } }

Joe said\t "Hello" to me!

Joe said\t ""Hello"" to me!

Joe said "Hello" to me!

Joe said ""Hello"" to me!

Answer

Correct Answer: Joe said\t "Hello" to me!

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169.
What is the following code correct output for the C# code snippet shown below? String s1 = "UpWork Skills Test"; String s2; s2 = s1.Substring(12, 3); Console.WriteLine(s2);

Tes

sTe

s T

sTe

lsT

Answer

Correct Answer: s T

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170.
What would be the output of following code snippet? { try { int a, b; b = 0; a = 10 / b; Console.WriteLine("A"); } catch(ArithmeticException e) { Console.WriteLine("B"); } Console.ReadLine(); }

a) A

b) B

c) Compile time error

d) Run time error

Answer

Correct Answer: b) B

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171.
What will be the output of given code snippet? class Program { static void Main(string[] args) { int[] nums = { 1, -2, 3, 0, -4, 5}; var posNums = from n in nums where n >= 0 select n; foreach (int i in posNums) Console.Write(i + " "); Console.WriteLine(); Console.ReadLine(); } }

a) "0 1 -2 -4 5"

b) "1 3 0 5"

c) "1 3 5"

d) Run time error

Answer

Correct Answer: b) "1 3 0 5"

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172.
Select the result of the given code snippet: class Program { static void Main(string[] args) { int[] nums = { 16, 9, 25}; var posNums = from n in nums where n > 0 select Math.Sqrt(n); Console.Write("The positive values in nums: "); foreach (int i in posNums) Console.Write(i + " "); Console.WriteLine(); Console.ReadLine(); } }

a) Code runs successfully and prints nothing.

b) Code runs successfully and prints required output.

c) Run time error!

d) Compile time error!

Answer

Correct Answer: b) Code runs successfully and prints required output.

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173.
What is the best way to copy the contents of one stream to another in .NET 4?

input.CopyTo(output);

public static void CopyStream(Stream input, Stream output) { byte[] buffer = new byte[32768]; int read; while ((read = input.Read(buffer, 0, buffer.Length)) > 0) { output.Write (buffer, 0, read); } }

public static void CopyTo(Stream input, Stream output) { int size = (input.CanSeek) ? Math.Min((int)(input.Length - input.Position), 0x2000) : 0x2000; byte[] buffer = new byte[size]; int n; do { n = input.Read(buffer, 0, buffer.Length); output.Write(buffer, 0, n); } while (n != 0); }

public static void CopyStream(Stream input, Stream output) { byte[] buffer = new byte[32768]; long TempPos = input.Position; while (true) { int read = input.Read (buffer, 0, buffer.Length); if (read <= 0) break; output.Write (buffer, 0, read); } input.Position = TempPos; }

Answer

Correct Answer: input.CopyTo(output);

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174.
How is Math.Pow() implemented in the .NET Framework?

Math.Pow operates on type floats, which are by definition accurate. float power = Math.Pow(x, 2);

Math.Pow operates on type doubles. Doubles are 64-bit floating point and have about 15-16 digits of precision in C#. Func<long, int, long> power = null; power = (i, p) => p == 1 ? i : i*power(i, p - 1); Console.WriteLine(power(15, 14));

Math.Pow operates on type integers. Int32 power = Math.Pow(x, 2);

Math.Pow operates on type decimals. Decimal power = Math.Pow(x, 2);

Answer

Correct Answer: Math.Pow operates on type doubles. Doubles are 64-bit floating point and have about 15-16 digits of precision in C#. Func<long, int, long> power = null; power = (i, p) => p == 1 ? i : i*power(i, p - 1); Console.WriteLine(power(15, 14));

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175.
Which of the following statements are true about Struct in C#?

Struct is a reference type.

It logically represents a single value, similar to primitive types.

Struct is Immutable.

It has an instance size smaller than 16 bytes.

Answer

Correct Answer: It logically represents a single value, similar to primitive types.
Struct is Immutable.
It has an instance size smaller than 16 bytes.

Note: This question has more than 1 correct answers

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176.
Which of the following statements is incorrect regarding the Dictionary and Hashtable data types in the .NET Framework?

Both are internally Hashtable.

Dictionary is faster than Hashtable for value types as Boxing and Unboxing does not take place.

Both are Generic types.

Both need immutable and unique keys.

Answer

Correct Answer: Dictionary is faster than Hashtable for value types as Boxing and Unboxing does not take place.

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177.
Which of the following can be used to expose a method as a field to the outside world?

property

indexer

delegate

event

enumerator

Answer

Correct Answer: property

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178.
Which statement(s) is/are incorrect in relation to the two functions below? 1. public static byte[] ReadFully(Stream input) { byte[] buffer = new byte[16*1024]; using (MemoryStream ms = new MemoryStream()) { int read; while ((read = input.Read(buffer, 0, buffer.Length)) > 0) { ms.Write(buffer, 0, read); } return ms.ToArray(); } } 2. public static byte[] ReadFully(Stream input) { using (MemoryStream ms = new MemoryStream()) { input.CopyTo(ms); return ms.ToArray(); } }

Both functions can be used to convert an input stream into a byte array.

#1 can be used in all versions of the .NET Framework, while #2 is only supported in the .NET Framework 4.0 and above.

Both functions will work in all .NET Framework versions.

None of these.

Answer

Correct Answer: #1 can be used in all versions of the .NET Framework, while #2 is only supported in the .NET Framework 4.0 and above.

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179.
Which of the following will return the absolute URL (ie. http://www.something.com/index.aspx) of the requested page (ASP.NET)?

HttpContext.Current.Request.Url.AbsolutePath;

HttpContext.Current.Request.Url.AbsoluteUri;

HttpContext.Current.Request.Url.Host;

HttpContext.Current.Request.Url.PathAndQuery;

Answer

Correct Answer: HttpContext.Current.Request.Url.AbsoluteUri;

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180.
When should the "as" keyword be used in C# ?

Every time when it is needed to safe cast object without exception use as: MyType a = myObj as MyType; if (a != null) a.SomeMethod();

It's good because: - It’s fast - It’ll complain if something is wrong

A "As" means one of two things: - Know for sure that this object actually is of this other type. Make it so, and if wrong, crash the program. - Know for sure that this object is not of this other type, but that there is a well-known way of converting the value of the current type to the desired type

In the case of "As" operator, to type cast, two steps are needed: - Check the Type using as - If it’s true then Type cast

Answer

Correct Answer: A "As" means one of two things: - Know for sure that this object actually is of this other type. Make it so, and if wrong, crash the program. - Know for sure that this object is not of this other type, but that there is a well-known way of converting the value of the current type to the desired type

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181.
What is the fundamental difference between double and decimal variable types?

Double is a base 2 fraction, whereas a decimal is a base 10 fraction.

Double is used in mathematical calculations, whereas a decimal is used in financial calculations.

Double is used to speed up calculations, whereas a decimal is used where exact precision is required.

Double is used for approximate values, whereas a decimal is used for exact values.

Answer

Correct Answer: Double is a base 2 fraction, whereas a decimal is a base 10 fraction.

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182.
Which of the following statements are correct?

If two objects are equal, then they must return the same value for GetHashCode().

If two objects return same value for GetHashCode(), then they must be equal.

If two objects are equal, then they must return different values for GetHashCode().

None of these.

Answer

Correct Answer: If two objects are equal, then they must return the same value for GetHashCode().

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183.
Which of the following code snippets are the correct way to convert a Single into a String in C#? (Choose all that apply.)

Single f = 7.5f; String s; s = (String) (f);

Single f = 7.5f; String s; s = Convert.ToString(f);

Single f = 7.5f; String s; s = f.ToString();

Single f = 7.5f; String s; s = CInt(f);

Single f = 7.5f; String s; s = CString(f);

Answer

Correct Answer: Single f = 7.5f; String s; s = Convert.ToString(f);
Single f = 7.5f; String s; s = f.ToString();

Note: This question has more than 1 correct answers

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184.
What is the purpose of the yield keyword in C#?

It's used in an iterator block to provide a value to the enumerator object or to signal the end of iteration.

It's used in an iterator block to provide a value to the anonymous object or to signal the end of iteration.

It's used only in a foreach block to provide a value to the enumerator object or to signal the end of iteration.

It's used only in a foreach block to provide a value to the anonymous object or to signal the end of iteration.

Answer

Correct Answer: It's used in an iterator block to provide a value to the enumerator object or to signal the end of iteration.

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185.
What will be the output of the following set of code? { int sum = 10; try { int i; for (i = -1; i < 3; ++i) sum = (sum / i); } catch (ArithmeticException e) { Console.WriteLine("0"); } Console.WriteLine(sum); Console.ReadLine(); }

a) 0

b) 0 5

c) 0 -10

d) Compile time error

Answer

Correct Answer: c) 0 -10

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186.
If 's1' and 's2' are references to two strings, then which of the following is the correct way to compare the two references?

s1 is s2

s1 = s2

s1 == s2

strcmp(s1, s2)

s1.Equals(s2)

Answer

Correct Answer: s1.Equals(s2)

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187.
Which of the following statements is correct about the difference between Static readonly and const?

Read only static are evaluated when code execution hits class reference (i.e.: new instance is created or static method is executed), and must have evaluated value by the time static constructor is done. Const is static by default and must have compilation-time value.

Read only static are evaluated when instance is created and must have set value by the time constructor exits. Const values are burned directly into the call-site; this is double edged.

Const is not static by default and must have compilation-time value. Read only static are evaluated when code execution hits class reference (i.e. new instance is created or static method is executed), and must have evaluated value by the time static constructor is done.

A const is a compile-time constant where as read-only allows a value to be calculated at run-time.

Answer

Correct Answer: Read only static are evaluated when code execution hits class reference (i.e.: new instance is created or static method is executed), and must have evaluated value by the time static constructor is done. Const is static by default and must have compilation-time value.

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188.
Which of the following is the object oriented way to handle run time errors? (Choose all that apply)

a) Error codes

b) HERRESULT

c) OnError

d) Exceptions

Answer

Correct Answer: d) Exceptions

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189.
How you can display different data at run time and design time?

a) One way of displaying data at run time and design time is to declare your data in XAML.

b) Another way of doing it is by declaring it in XAML by using various data attributes from the designer XML namespace. With a d: prefix, this namespace is typically declared.

c) All of the above

Answer

Correct Answer: c) All of the above

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190.
Which of the following stream class method you can use for the close connection?

function close()

void close()

static close()

coneection close()

Answer

Correct Answer: void close()

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191.
What is output for the following set of Code? static void Main(string[] args) { String obj = "hello"; String obj1 = "world"; String obj2 = obj; string s = obj+" "+obj1; Console.WriteLine(s.IndexOf('r')); Console.ReadLine(); }

a) 7

b) 8

c) 9

d) 10

Answer

Correct Answer: b) 8

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192.
Choose the incorrect statement about delegates?

a) delegates are not type safe

b) delegates cannot be used to implement callback notification

c) delegate is a user defined type

d) delegates permits execution of a method in an asynchronous manner

Answer

Correct Answer: a) delegates are not type safe
b) delegates cannot be used to implement callback notification

Note: This question has more than 1 correct answers

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193.
Which of the following best describes the correct usage of exception handling over conventional error handling approaches? a) Errors can be ignored but exceptions cannot be ignored. b) Exception handling allows separation of the program’s logic from the error handling logic, making software more reliable and maintainable. c) try – catch – finally structure allows guaranteed clean up in event of errors under all circumstances.

a, only

b, only

c, only

a and b

a and c

b and c

a, b and c

Answer

Correct Answer: a, b and c

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194.
Strings built using the String class are immutable, whereas those built using the StringBuilder class are mutable?

True

False

Will depend on the context

Answer

Correct Answer: True

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195.
Which of the following C# code snippets correctly copies the contents of one string into another?

String s1 = "UpWork"; String s2; s2 = s1;

String s1 = "UpWork"; String s2; s2 = String.Concat(s1, s2);

String s1 = "UpWork"; String s2; s2 = String.Copy(s1);

String s1 = "UpWork"; String s2; s2 = s1.Replace();

String s1 = "UpWork"; String s2; s2 = s2.StringCopy(s1);

Answer

Correct Answer: String s1 = "UpWork"; String s2; s2 = String.Copy(s1);

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196.
Which of the following are true? 1) Int32.Parse() can only convert strings. 2) Convert.ToInt32() can take any class that implements IConvertible , and returns 0 when the argument is null.

a) 2

b) Both 1,2

c) 1

d) None of the mentioned

Answer

Correct Answer: b) Both 1,2

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197.
To implement delegates, the necessary condition is?

a) class declaration

b) inheritance

c) run time polymorphism

d) exceptions

Answer

Correct Answer: a) class declaration

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198.
In C#, an interface cannot contain which signature?

Methods

Properties

Constructors

Indexers and Events

Answer

Correct Answer: Constructors

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199.
What does the given code snippet specify? public Thread(ThreadStart start) = = = = = a) Initialization of a new instance of the Thread class. b) Declaration of a thread constructor.

a, only.

b, only.

None of these.

a and b.

Answer

Correct Answer: a and b.

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200.
Which statement(s) is/are correct?

When we use Debug class for tracing, it will work in builds which have the debug symbol defined.

When we use Trace class for tracing, it will work in builds which have the Trace symbol defined.

None

Answer

Correct Answer: When we use Debug class for tracing, it will work in builds which have the debug symbol defined.
When we use Trace class for tracing, it will work in builds which have the Trace symbol defined.

Note: This question has more than 1 correct answers

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201.
Which construct is used to do a left outer join in LINQ?

DefaultIfEmpty method

left join clause

Using a foreach loop

None of the above

Answer

Correct Answer: DefaultIfEmpty method

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202.
Correct way to define a value 6.28 in a variable ‘a’ where value cannot be modified ? (Choose all that apply)

a) #define a 6.28F;

b) a = 6.28F;

c) const float a = 6.28F;

d) const float a; a = 6.28F;

Answer

Correct Answer: c) const float a = 6.28F;

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203.
How can we use COM components in .Net?

a) We can generate Wrapper class using Visual Studio and can place it in BIN directory.

b) We can use the type library importer tool - Tlbimp.exe

c) We can use the Interopservices. System.Runtime.Interopservices namespace provides TypeLib Converter that has methods to convert COM classes and interface in to assembly metadata.

d) We can create our own custom wrappers.

e) All of the above

Answer

Correct Answer: e) All of the above

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204.
What is OCP?

OCP,means that a class should be open for extension, but closed for modification

OCP,means consumers of your class should be able to customize its usage

OCP, Oriented computer programing

Answer

Correct Answer: OCP,means that a class should be open for extension, but closed for modification
OCP,means consumers of your class should be able to customize its usage

Note: This question has more than 1 correct answers

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205.
Which of the following keyword you can used for correct implementation of an interface in C#.NET?

Composite

Interface

Mediator

Memento

Answer

Correct Answer: Interface

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206.
Number of threads that exists for each of the processes that occurs in the program?

atmost 1

atleast 1

only 1

Both b & c

Answer

Correct Answer: atmost 1
only 1

Note: This question has more than 1 correct answers

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207.
Which of the following exceptions cannot be thrown by the Delete() method of the FileInfo class?

IOException

SecurityException

UnauthorizedAccessException

InvalidOperationException

Answer

Correct Answer: InvalidOperationException

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208.
Which statement below is correct?

$ matches the beginning of a line.

^ matches the end of a line.

( opens a group.

Answer

Correct Answer: ( opens a group.

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209.
Suppose a HashTable named "upwork" maintains a collection of project areas and the name of the best freelancer in each area. Which of the following is the correct way to find out whether the project area "C# programming" is present in the collection or not?

upwork.HasValue("C# programming");

upwork.HasKey("C# programming");

upwork.ContainsKey("C# programming");

upwork.ContainsValue("C# programming");

upwork.ContainsArea("C# programming");

Answer

Correct Answer: upwork.ContainsKey("C# programming");

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210.

Which of the following is not true about interfaces in C#?

An interface is a contract that a class must implement

An interface can be instantiated as a reference type

An interface can inherit from multiple base-interfaces

A class can implement more than one interfaces

Answer

Correct Answer: An interface can be instantiated as a reference type

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211.
Which of the following are correct in relation to the above C#.Net code? Stack st = new Stack(); st.Push("UpWork"); st.Push(9.2); st.Push(6); st.Push('i'); st.Push(false);

The same Stack collection cannot be used to store dissimilar elements like "UpWork", 9.2, and 6.

Stacks can never store Boolean values.

The fourth call to Push(), "i" should have been used instead of 'i'.

To store dissimilar elements in a Stack collection, the alternative menthod PushAnyType() should have been used instead.

The above code works fine.

Answer

Correct Answer: The same Stack collection cannot be used to store dissimilar elements like "UpWork", 9.2, and 6.

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212.

Consider the following C# code, What output will be printed on the console? enum Color: int { Blue, Red, Green, Yellow, Orange } int color = (int)Color.Green; Console.WriteLine("{0} and {1}", color, Color.Yellow);

2 and Yellow

3 and Yellow

2 and 3

3 and 4

Answer

Correct Answer: 2 and Yellow

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213.
What will be the output of the given code snippet below? static void Main(string[] args) { int i = 15 ; for( ; ; ) { Console.Write(i + " "); if (i >= -10) i -= 3; else break; } }

10 12 9 6 3 0 -3 -6 -9 -12

10 12 14 9 3 0 -3 -6 -9 -12

15 12 9 6 3 0 -3 -6 -9 -12

15 12 9 6 3 1 -3 -6 -9 -10

Answer

Correct Answer: 15 12 9 6 3 0 -3 -6 -9 -12

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214.

What is the output when following statement is executed? static void Main(string[] args){ int i = 1, j; do { for (j = 1; ; j++) { if (i == j) continue; Console.WriteLine(i + " " + j); } i++; } while (i < 3); Console.ReadLine(); }

Run time error

Compile time error

11 , 12 , 21,13

10 , 11 , 12,14

Answer

Correct Answer: 11 , 12 , 21,13

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215.

What is the output when following code is executed? using System; using StringBuilder; namespace Text { class Program { public static void Main(string[] args) { StringBuilder sb = new StringBuilder("hello world in c#"); sb.Insert(4, "example"); Console.WriteLine(sb); Console.ReadLine(); } } }

Runtime time error

hello world in c# good

Compile time error

program run but crash

Answer

Correct Answer: Compile time error

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216.

In Constructor overloading, n number of __ can be created for the same class?

Functions

Methods

Constructors

Objects

Answer

Correct Answer: Constructors

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217.

Consider the following code output? static void Main(string[] args){ int i, j = 1, k; for (i = 0; i < 3; i++) { k = j++ - ++j; Console.Write(k + " "); } }

Run time error

Infinity

Compile time error

Answer

Correct Answer: Infinity

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218.
Which of the following is the correct way to call the function Jobs(int i) of the UpWork class given below? class UpWork { public int Jobs(int i) { Console.Writeline("UpWork!"); return 0; } }

delegate void del(int i); UpWork u = new UpWork(); del d = new del(ref u.Jobs); d(10);

delegate int del(int i); UpWork u = new UpWork(); del = new delegate(ref Jobs); del(10);

UpWork u = new UpWork(); delegate void del = new delegate(ref Jobs); del(10);

delegate int del(int i); del d; UpWork u = new UpWork(); d = new del(ref u.Jobs); d(10);

Answer

Correct Answer: delegate int del(int i); del d; UpWork u = new UpWork(); d = new del(ref u.Jobs); d(10);

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219.
Which of the following statements is correct about implementing interfaces explicitly? interface I1 { void example(); }

class C : I1 { void I1.example(){} }

class C : I1 { void example(){} }

class C { void example(){} }

class C { void I1.example(){} }

Answer

Correct Answer: class C : I1 { void example(){} }

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220.
What will be the output of the following Main program in a C# console application (Assume required namespaces are included): static void Main(string[] args) { Guid g = new Guid("iamnotguid"); Console.WriteLine(g); Console.ReadLine(); }

iamnotguid

It will throw a compilation error.

It will throw an error at runtime.

None of these.

Answer

Correct Answer: It will throw an error at runtime.

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221.
What will be the output of the following Main program in a C# console application (Assume required namespaces are included): static void Main(string[] args) { string s = null + true; Console.WriteLine(s); Console.ReadLine(); }

True

It will throw a compilation error.

It will throw an error at runtime.

False

Answer

Correct Answer: True

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222.
Which of the following code snippets returns the type of T, based on the code below? List< T > myList = new List< T >;

Type type = myList.GetType().GetGenericArguments()[0];

Type type = myList.GetType().GetProperty("Item").PropertyType;

Type type = typeof(T);

Type type = myList.AsEnumerable().SingleOrDefault().GetType();

Answer

Correct Answer: Type type = typeof(T);

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223.
Which of the following statements are true about the following C#.Net code? String s1, s2; s1 = "UpWork"; s2 = "UpWork";

Creating String objects requires use of the word 'new'.

Only one variable will be created.

's1' and 's2' both will refer to the same variable.

Two variable will be created, one pointed to by 's1' and another pointed to by 's2'.

's1' and 's2' are references to the same variable.

Answer

Correct Answer: Only one variable will be created.
's1' and 's2' both will refer to the same variable.
's1' and 's2' are references to the same variable.

Note: This question has more than 1 correct answers

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224.
Which of the following is the correct way to calculate "Age" from date of birth? Example : DateTime bday= DateTime((1990, 10, 3));

DateTime today = DateTime.Today; int age = today.Year - bday.Year;

DateTime today = DateTime.Today; int age = today.Year() - bday.Year();

int age = (int) ((DateTime.Now - bday).TotalDays/365.255);

int age = ((DateTime.Now - bday).TotalDays/366);

Answer

Correct Answer: DateTime today = DateTime.Today; int age = today.Year - bday.Year;

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225.
Which of the following are ways of ensuring that a user enters an integer value in a WinForms application?

In a textbox, by handling the textBox_KeyPress event and writing appropriate code in it.

By using the masked Text Box control.

By using the Numeric Up Down control.

All of these.

Answer

Correct Answer: All of these.

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226.
How can you code to display “This is XAML” in XAML?

a) pages xmlns= "" ""> <TextBlock> This is XAML </TextBlock> </Pages>

b) page xmlns= "" ""> <Text> This is XAML </Text> </Page>

c) Page xmlns= "" ""> <TextBlock> This is XAML </TextBlock> </Page>

Answer

Correct Answer: c) Page xmlns= "" ""> <TextBlock> This is XAML </TextBlock> </Page>

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227.

Four threads are working simultanmeously on an ArrayList object. How many enumerators will exit in this case?

None of the above

Answer

Correct Answer: 4

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228.
Which of the following statements is false in relation to following method? static byte[] GetBytes(string str) { byte[] bytes = new byte[str.Length * sizeof(char)]; System.Buffer.BlockCopy(str.ToCharArray(), 0, bytes, 0, bytes.Length); return bytes; }

It returns a byte array representation of a string.

It will throw an exception if str is passed as a null.

None of these.

Answer

Correct Answer: None of these.

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229.
Which of the following is the correct output for the C# code snippet? String s1 = "UpWork"; String s2; s2 = s1.Insert(4, "Project"); Console.WriteLine(s2);

UpWoProjectrk

UpWoPr

UpWorProjectk

UpWorP

UpWorkProject

UpWork

Answer

Correct Answer: UpWorProjectk

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230.
Which of the following is a valid C# statement?

2 * 3;

int[][] intArray = new int[12][]; intArray[0] = new int[5][5];

int counter=0; checked { counter++; }

static const int i = 0;

Answer

Correct Answer: int counter=0; checked { counter++; }

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231.
What will happen if the value of nNum is 2 and the following code is compiled and executed? switch(nNum) { case 1: Console.WriteLine("nNum = 1"); break; case 2: Console.WriteLine("nNum = 2"); default: Console.WriteLine("nNum is not 1 nor 2"); break; }

The code will output: nNum = 2

The code will output: nNum = 2 nNum is not 1 nor 2

The code will output: nNum = 1 nNum = 2

Compiler error

Answer

Correct Answer: Compiler error

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232.
Consider the following declaration in C#, Which statement is true about this declaration? int[][] array;

It declares a two dimensional array of integers

It declares a a single-dimensional array of single-dimensional arrays of type int

It is not a valid C# declaration

Answer

Correct Answer: It declares a a single-dimensional array of single-dimensional arrays of type int

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233.
What is multithreaded programming?

a) It’s a process in which two different processes run simultaneously

b) It’s a process in which two or more parts of same process run simultaneously

c) Its a process in which many different process are able to access same information

d) Its a process in which a single process can access information from many sources

Answer

Correct Answer: b) It’s a process in which two or more parts of same process run simultaneously

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234.
Which of the following is not a relational operator in C#?

Answer

Correct Answer: <<

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235.
Select the type of multitasking methods that exist?

a) process based

b) thread based

c) only a

d) Both a & b

Answer

Correct Answer: d) Both a & b

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236.
What does the following declaration specify? MethodInfo[] GetMethods()

a) Returns an array of MethodInfo objects

b) Returns a list of the public methods supported by the type by using GetMethods()

c) Both a & b

d) None of the mentioned

Answer

Correct Answer: c) Both a & b

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237.
Choose the correct statement about process-based multitasking?

a) a feature that allows our computer to run two or more programs concurrently

b) a program that acts as a small unit of code that can be dispatched by the scheduler

c) Only b

d) Both a & b

Answer

Correct Answer: d) Both a & b

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238.
Choose the correct statements about the LINQ?

The main concept behind the linq is query

linq makes use of foreach loop to execute the query

It is not required that linq should make use of IEnumerable interface

None of the above

Answer

Correct Answer: The main concept behind the linq is query
linq makes use of foreach loop to execute the query

Note: This question has more than 1 correct answers

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239.
What are the general kinds of XAML elements?

Root Elements

Panel Elements

Control Elements

Geometric Elements

All of the above

Answer

Correct Answer: All of the above

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240.
Which of the following is the best way of creating a generic method constraining T to an Enum?

public static class EnumUtils { public static T ParseEnum<T>(string value, T defaultValue) where T : struct, IConvertible { if (string.IsNullOrEmpty(value)) return defaultValue; foreach (T item in Enum.GetValues(typeof(T))) { if (item.ToString().ToLower().Equals(value.Trim().ToLower())) return item; } return defaultValue; } }

public static class EnumUtils { public static T ParseEnum<T>(string value, T defaultValue) where T : Enum { if (!typeof(T).IsEnum) throw new ArgumentException("T must be an enumerated type"); if (string.IsNullOrEmpty(value)) return defaultValue; foreach (T item in Enum.GetValues(typeof(T))) { if (item.ToString().ToLower().Equals(value.Trim().ToLower())) return item; } return defaultValue; } }

public static class EnumUtils { public static T ParseEnum<T>(string value, T defaultValue) where T : Enum { if (string.IsNullOrEmpty(value)) return defaultValue; foreach (T item in Enum.GetValues(typeof(T))) { if (item.ToString().ToLower().Equals(value.Trim().ToLower())) return item; } return defaultValue; } }

public static class EnumUtils { public static T ParseEnum<T>(string value, T defaultValue) where T : struct, IConvertible { if (!typeof(T).IsEnum) throw new ArgumentException("T must be an enumerated type"); if (string.IsNullOrEmpty(value)) return defaultValue; foreach (T item in Enum.GetValues(typeof(T))) { if (item.ToString().ToLower().Equals(value.Trim().ToLower())) return item; } return defaultValue; } }

Answer

Correct Answer: public static class EnumUtils { public static T ParseEnum<T>(string value, T defaultValue) where T : struct, IConvertible { if (!typeof(T).IsEnum) throw new ArgumentException("T must be an enumerated type"); if (string.IsNullOrEmpty(value)) return defaultValue; foreach (T item in Enum.GetValues(typeof(T))) { if (item.ToString().ToLower().Equals(value.Trim().ToLower())) return item; } return defaultValue; } }

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241.
Which of the following statements is correct about the ref and out keywords?

ref tells the compiler that the object is initialized before entering the function, while out tells the compiler that the object will be initialized inside the function.

out tells the compiler that the object is initialized before entering the function, while ref tells the compiler that the object will be initialized inside the function.

Both ref and out tells the compiler that the object is initialized before entering the function.

Both ref and out tells the compiler that the object will be initialized inside the function.

Answer

Correct Answer: ref tells the compiler that the object is initialized before entering the function, while out tells the compiler that the object will be initialized inside the function.

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242.
Which of the following statements are false regarding the 3 timer classes provided by the .NET framework? a) System.Windows.Forms.Timer b) System.Timers.Timer c) System.Threading.Timer

System.Windows.Forms.Timer requires Windows Forms (WinForms) whereas System.Timers.Timer and System.Threading.Timer do not.

The event handler of all of the three Timers call the timer event handler on a worker thread obtained from the Common Language Runtime (CLR) thread pool.

The System.Threading.Timer class does not support inheritance but the System.Timers.Timer and the System.Windows.Forms.Timer classes do support it.

System.Timers.Timer is regarded as thread-safe whereas System.Windows.Forms.Timer and System.Threading.Timer are not.

Answer

Correct Answer: The event handler of all of the three Timers call the timer event handler on a worker thread obtained from the Common Language Runtime (CLR) thread pool.

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243.
How can a function be defined in a derived class having the same name as a non-virtual function in the base class?

This can be done by adding the function definition in the derived class. The function in the derived class will automatically hide the function in the parent class.

By using the new keyword

By using the override keyword

It cannot be done; the base and derived classes cannot have non-virtual functions with the same name.

Answer

Correct Answer: By using the override keyword

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244.
Consider the following statements and pick the most appropriate option: Statement 1: Value type variables store their data on the heap. Statement 2: Reference type variables store their data on the stack.

Statement 1 is true and Statement 2 is false.

Statement 2 is true and Statement 1 is false.

Both Statements 1 and 2 are true.

Both Statements 1 and 2 are false.

Answer

Correct Answer: Both Statements 1 and 2 are false.

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245.
What is the purpose of ?? (Two question mark) in C#? Example : Class object ??= new Class();

It is used to create null able object.

It is the null coalescing operator, similar to the ternary (immediate-if) operator.

It is used to create an optimized object.

It is used to create an optimized nullable object.

Answer

Correct Answer: It is the null coalescing operator, similar to the ternary (immediate-if) operator.

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246.
What does the following function signature denote? public static intCharLength(this string inputStr)

CharLength is an Extension method which can be used with string variables.

CharLength is an Extension method which can be used with integer variables.

CharLength is a simple method which takes a string as input and return an integer.

None of these.

Answer

Correct Answer: CharLength is an Extension method which can be used with string variables.

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247.
What is the output of the following code snippet?
public class MyClass { public int X { get; set; } }
public struct MyStruct { public int X { get; set; } }
class Program { static void Main(string[] args) { MyClass classObj1 = new MyClass(); classObj1.X=12; MyClass classObj2 = classObj1; classObj2.X = 15; Console.WriteLine(classObj1.X); Console.WriteLine(classObj2.X); MyStruct structObj1 = new MyStruct(); structObj1.X = 12; MyStruct structObj2 = structObj1; structObj2.X=15; Console.WriteLine(structObj1.X); Console.WriteLine(structObj2.X); Console.ReadLine(); } }

15 15 12 12

12 15 12 15

15 15 12 15

15 15 15 15

Answer

Correct Answer: 15 15 12 15

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248.
What will be the value of the result variable after these two statements? int num1 = 10, num2 = 9; int result = num1 & num2;

109

Answer

Correct Answer: 8

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249.
In the .NET framework, what are the options available for packaging?

CAB

EXE

MSI

All of these

Answer

Correct Answer: All of these

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250.
Two users, Monique and James are using an MIS system implemented using ADO.NET. The data refresh time in the system is set to 15 minutes. James changed the mailing address of a customer named Majda, and updated the database. Before the database refresh, Monique also updated the same customer's address as per her pending requests folder. What will happen when Monique saves the changes?

Changes made by Monique will be saved by the database.

Changes made by Monique will be ignored and nothing unusual happens.

DBConcurrencyException will be thrown.

DBException will be thrown.

Answer

Correct Answer: Changes made by Monique will be saved by the database.

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251.
Which of the following is the best way to measure the performance of a function?

DateTimestartTime = DateTime.Now; PerformWork(); DateTimeendTime = DateTime.Now; TimeSpantotalTimeTaken = endTime.Subtract(startTime);

Stopwatch.StartNew(); PerformWork Stopwatch sw = (); sw.Stop();

DateTimestartTime = DateTime.UtcNow; PerformWork(); DateTimeendTime = DateTime.UtcNow; TimeSpantotalTimeTaken = endTime.Subtract(startTime);

long startTime = Stopwatch.GetTimestamp(); PerformWork(); long endTime = Stopwatch.GetTimestamp(); long totalTimeTaken = (endTime - startTime)/Stopwatch.Frequency;

Answer

Correct Answer: Stopwatch.StartNew(); PerformWork Stopwatch sw = (); sw.Stop();

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252.
If i == 0, why is (i += i++) == 0 in C#?

//source code i += i++; //abstract syntax tree += / \ ii (post) \ ++

// source code i += i++; //abstract syntax tree += / \ i ++ (post) \ i First, i++ returns 0. Then i is incremented by 1. Lastly i is set to the initial value of i which is 0 plus the value i++ returned, which is zero too. 0 + 0 = 0.

inti = 0; i = i + i; i + 1;

int ++(ref inti) { int c = i; i = i + i; return c;}

Answer

Correct Answer: inti = 0; i = i + i; i + 1;

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253.
Which of the following is the correct statement to combine two URL(s)?

Uri baseUri = new Uri(http://www.Domaine.com); Uri myUri = new Uri(“folder/.page”, baseUri);

String baseUr =:”http://DomainName.com”; Uri myUri = uri(baseUri, “ folder/page.htm”,htm”);

String baseUrl = http://DomainName.com UrimyUri = new Uri(“folder/page.htm”, baseUel);

UribaseUri = new Uri(http://DomainName.com.com); UrimyUri = new Uri(, “folder/page.htm:”);

Answer

Correct Answer: UribaseUri = new Uri(http://DomainName.com.com); UrimyUri = new Uri(, “folder/page.htm:”);

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254.
Which is the following is the correct way to convert a Byte Array to a Hexadecimal string, and vice versa?

Static readonly char [ ] _hexDigits = “0123456789abcdef”. ToCharArray(); Public static string ToHexString(this byte[] bytes { Char[] digits = new char [bytes. Length * 2]; For (int I = 0; i<bytes.Length; i++) { Int d1, d2; D1 = Math. DivRem(bytes[i], 16, out d2); Digits[2 * i] = _hexDigits[d1]; Digits[2 * 1 + 1] = _hexDigits[d2]; } Return new string(digits); }

Public static byte [] stringToByteArray(String hezx) { IntNumberChars = hex. Length/; Byte[] bytes = new bytes [numberChars]; StringReadingsr = new StringReader (hex); for (inti = 0; iNumberChars; i++) Bytes[i] = convert. ToByte(new string(new char[2]{(char)sr.Read(), (char)sr.Read(), (char)sr.Read()}), 16); Return bytes; }

System.Runtime. Remoting.metadata.w3cxsd2001; Public byte[] GetStringToBytes(string value) { SoapHexBinaryahb = SoapHexBinary. Parse(value); } Public string GetBytesToString(byte[] value) { SoapHexBinaryshb = new soaphHexBinary(value); Return shb. ToString(); }

String. Join(string. Empty,Array.ConvertAll(bytes, x => x. ToString(“x2”)));

Answer

Correct Answer: String. Join(string. Empty,Array.ConvertAll(bytes, x => x. ToString(“x2”)));

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255.
Can a function be overload with the same number and types of arguments (parameters), but with a different return type?

Yes

Yes, but only if the function is static.

Yes, but only if the function is virtual.

Answer

Correct Answer: No

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256.
Which of the following can be used to expose a method as a filed to the outside world?

Property

Indexer

Delegate

Even

Enumerator

Answer

Correct Answer: Property

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