Ultimate C Sharp Test - 79+ MCQs: C# test: Evaluate Your Skills with C# Questions and Answers

1. Which keyword is used to define a class in C#?

function

class

method

interface

2. What is the purpose of the 'using' directive in a C# program?

To declare variables

To define classes

To import namespaces

To create objects

3. What is 'asynchronous programming' in C#?

A technique for running code sequentially.

A method for executing code in parallel.

A way to write code that can perform non-blocking operations and continue executing other tasks.

A way to optimize database queries in C#.

4. What is 'boxing' and 'unboxing' in C#?

Boxing is the process of converting a value type to a reference type, and unboxing is the reverse operation.

Boxing is the process of converting a reference type to a value type, and unboxing is the reverse operation.

Boxing and unboxing are techniques for optimizing memory usage in C#.

Boxing and unboxing are used for handling exceptions in C#.

5. Which C# keyword is used to handle exceptions?

try

catch

throw

exception

6. In C#, what keyword is used to define a constant?

const

constant

var

readonly

7. Which C# keyword is used to define an enumeration?

enum

class

struct

interface

8. What does C# stand for?

C Sharp

C Plus

C Hash

C Number

9. What is the purpose of the 'interface' keyword in C#?

To define a class

To create an object

To declare a constant

To define a contract for classes to implement

10. What is the purpose of 'extension methods' in C#?

To extend the duration of method execution.

To add new methods to existing types without modifying their source code.

To optimize the performance of methods in C#.

To create methods with variable numbers of parameters.

11. What is the default access modifier for class members in C#?

public

private

protected

internal

12. Which C# keyword is used to indicate that a class cannot be inherited from?

inherit

final

sealed

abstract

13. What is the purpose of the 'try', 'catch', and 'finally' blocks in C#?

To define loops

To declare variables

To handle exceptions

To create conditions

14. How do you define a property in a C# class?

property myProperty { get; set; }

int myProperty { }

function myProperty() { }

var myProperty = 10;

15. What is the purpose of the 'using' statement in C# when working with resources like files or database connections?

To declare a variable

To import namespaces

To create an object

To ensure proper resource cleanup

16. How do you define a constructor in a C# class?

constructor() { }

init() { }

void constructor() { }

public ClassName() { }

17. Which C# keyword is used to indicate that a method can be overridden in a derived class?

override

virtual

abstract

sealed

18. How do you define a constant value in C#?

const myValue = 10;

constant myValue = 10;

var myValue = 10;

readonly myValue = 10;

19. Which C# keyword is used to define a new instance of a class?

new

instance

create

instantiate

20. What is the C# syntax for creating a new instance of a class?

new myClass();

create myClass();

instantiate myClass();

instance myClass();

21. What is 'tuple' in C#?

A data structure that stores a single value.

A type of exception in C#.

A collection of key-value pairs.

An ordered collection of elements with a specific type.

22. Which C# data type is used to represent a single character?

char

string

byte

int

23. What is the C# operator for equality?

24. Which C# data type is used to represent true or false values?

bool

int

double

string

25. What is the purpose of the 'foreach' loop in C#?

To define a new variable

To iterate over elements of a collection

To create an infinite loop

To execute code once

26. What is the entry point of a C# program?

main()

start()

entry()

Main()

27. What is 'nullable types' in C#?

Types that cannot be assigned a value.

Types that are automatically initialized to null.

Types that can represent both a value and a lack of a value (null).

Types that have fixed size and cannot be resized.

28. What is the purpose of the 'finally' block in a try-catch-finally statement?

To catch exceptions

To handle errors

To execute code regardless of whether an exception is thrown or not

To define variables

29. What is the purpose of the 'using' directive in C#?

It is used to define custom namespaces.

It is used to declare variables.

It is used to include external libraries and namespaces.

It is used to specify access modifiers for class members.

30. What is the difference between 'sealed' and 'abstract' classes in C#?

'sealed' classes cannot be inherited, while 'abstract' classes are meant to be inherited and cannot be instantiated.

'sealed' classes are meant to be inherited and cannot be instantiated, while 'abstract' classes cannot be inherited.

'sealed' classes and 'abstract' classes are the same in C#.

There is no such thing as 'sealed' or 'abstract' classes in C#.

C# MCQ Test 3