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

1. What is the purpose of the 'base' keyword in C#?

It is used to access the base class's constructor.

It is used to define a base class for inheritance.

It is used to access the base class's static members.

It is used to specify access modifiers for class members.

2. 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.

3. What is the C# syntax for a for loop?

for (int i = 0; i < 10; i++) { }

foreach (int i in myArray) { }

while (i < 10) { }

do { } while (i < 10);

4. 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#.

5. What is 'method overloading' in C#?

A way to override base class methods.

A technique for creating methods with the same name but different parameters in the same class.

A method for calling methods from another class.

A way to define custom operators in C#.

6. In C#, what is the purpose of the 'StringBuilder' class?

To define variables

To build strings efficiently

To create loops

To perform mathematical operations

7. What is 'dependency injection' in C#?

A technique for injecting errors into code for testing purposes.

A method for injecting database queries into code for performance optimization.

A design pattern that allows objects to receive their dependencies from an external source rather than creating them internally.

A way to inject external libraries into a C# application.

8. What is 'generics' in C#?

A way to define classes with generic parameters.

A technique for optimizing memory usage in C#.

A method for overriding base class methods.

A way to define custom attributes.

9. In C#, what keyword is used to create an instance of a class?

create

new

instance

instantiate

10. In C#, what keyword is used to define a class?

class

define

struct

new

11. 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

12. What is the purpose of the 'this' keyword in C#?

To create a new instance of a class

To reference the current instance of a class

To declare a constant

To define a new variable

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

To declare variables

To define classes

To import namespaces

To create objects

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

static void myMethod() { }

void static myMethod() { }

public myMethod() { }

static public void myMethod() { }

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

try

catch

throw

exception

16. Which C# data type is used to store a single character?

char

string

character

letter

17. What is the purpose of the 'break' statement in a switch statement in C#?

To exit the switch statement

To continue to the next case

To skip the current case

To return a value

18. Which of the following is a reference type in C#?

int

double

string

array

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

To perform arithmetic operations

To check the type of an object

To define a new variable

To create an array

20. How do you define an array in C#?

array myArray = [1, 2, 3];

int[] myArray = {1, 2, 3};

int[] myArray = new int[3];

list myArray = [1, 2, 3];

21. Which C# operator is used to compare two values for equality?

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

const

constant

var

readonly

23. What is the C# operator for multiplication?

24. What is the C# syntax for a switch statement?

switch (condition) { case 1: break; default: break; }

if (condition) { } else { }

for (int i = 0; i < 10; i++) { }

while (i < 10) { }

25. What is 'garbage collection' in C#?

A process for removing unused namespaces from code.

A method for compressing data in memory to save space.

An automatic memory management technique for reclaiming unused objects and freeing up memory.

A way to optimize database queries in C#.

26. 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

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

function

method

def

public

28. 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#.

29. Which C# data type is used to store decimal numbers with high precision?

int

double

decimal

float

30. In C#, how do you declare a constant variable?

const myVar = 10;

constant myVar = 10;

final myVar = 10;

var constant myVar = 10;

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

public

private

protected

internal

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

override

virtual

abstract

sealed

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

property myProperty { get; set; }

int myProperty { }

function myProperty() { }

var myProperty = 10;

34. What is the purpose of the 'using' statement in C#?

To include external libraries

To declare variables

To define classes

To create objects

35. 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.

36. Which C# keyword is used to exit a loop prematurely?

break

continue

return

exit

37. What is the purpose of the 'volatile' keyword in C#?

It indicates that a variable cannot be modified.

It specifies a variable's data type.

It ensures that variable access is synchronized between multiple threads.

It defines a constant value.

38. What is a 'delegate' in C#?

A pointer to a function.

A reference to a class instance.

A collection of key-value pairs.

A keyword for declaring variables.

39. What is the default access modifier for class members in C# if no access modifier is specified?

public

private

protected

internal

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

const myValue = 10;

constant myValue = 10;

var myValue = 10;

readonly myValue = 10;

C# MCQ Test 2