100 Multiple Choice Questions & Answers on C#

Are you ready to test your knowledge and sharpen your skills in C# programming? Whether you’re a beginner looking to solidify your understanding or an experienced developer seeking a fun challenge, this blog post is here to help you. We have compiled a collection of 100 multiple-choice questions and answers on C# that cover a wide range of topics, allowing you to assess your grasp of the language.

C# is a powerful programming language widely used for developing a variety of applications, including desktop software, web applications, and mobile apps. Having a strong foundation in C# is essential for any aspiring or professional software developer. By diving into these multiple-choice questions, you’ll not only gauge your knowledge but also gain insights into different aspects of C# programming.

Question	Option A	Option B	Option C	Option D	Answer
1. Which of the following is NOT a primitive data type in C#?	int	double	string	bool	string
2. What is the default access modifier for a class member in C#?	public	private	protected	internal	private
3. What is the purpose of the var keyword in C#?	To implicitly declare a local variable with inferred type	To create an instance of a class	To perform arithmetic calculations	To define a loop construct	To implicitly declare a local variable with inferred type
4. Which keyword is used to define a constant in C#?	const	final	static	constant	const
5. What is the purpose of the using statement in C#?	To import namespaces or define resource scope	To compare two variables	To perform logical operations	To define a loop construct	To import namespaces or define resource scope
6. Which of the following is NOT a valid access modifier in C#?	public	private	protected	friendly	friendly
7. What is the purpose of the static keyword in C#?	To define class-level variables or methods	To create multiple instances of a class	To prevent a class from being inherited	To throw an exception	To define class-level variables or methods
8. Which of the following is NOT a valid C# loop statement?	for	while	until	do-while	until
9. What is the purpose of the abstract keyword in C#?	To define a base class or method that must be overridden	To perform bitwise operations	To manage memory allocation for objects	To exit a loop or switch statement	To define a base class or method that must be overridden
10. Which keyword is used to inherit a class in C#?	inherits	extends	implements	derives	inherits

Question	Option A	Option B	Option C	Option D	Answer
11. What is the purpose of the delegate keyword in C#?	To define a type that represents a method signature	To perform mathematical calculations	To define a conditional statement	To compare two variables	To define a type that represents a method signature
12. Which of the following is NOT a valid C# access modifier?	public	private	protected	internal	internal
13. What is the purpose of the try-catch statement in C#?	To handle exceptions and perform error handling	To declare a variable	To define a loop construct	To perform logical operations	To handle exceptions and perform error handling
14. Which keyword is used to create an instance of a class in C#?	new	create	instance	instantiate	new
15. What is the purpose of the interface keyword in C#?	To define a contract for implementing classes	To perform arithmetic operations	To define a loop construct	To compare two variables	To define a contract for implementing classes
16. Which of the following is NOT a valid C# conditional operator?	>	<	==	<>	<>
17. What is the purpose of the foreach statement in C#?	To iterate over elements in a collection or array	To sort elements in a collection	To perform bitwise operations	To exit a loop or switch statement	To iterate over elements in a collection or array
18. Which keyword is used to prevent a class from being inherited in C#?	sealed	static	final	protected	sealed
19. What is the purpose of the StringBuilder class in C#?	To create mutable strings	To compare two variables	To manage memory allocation for objects	To define a base class	To create mutable strings
20. Which of the following is NOT a valid C# exception handling keyword?	try	catch	finally	else	else

Question	Option A	Option B	Option C	Option D	Answer
21. What is the purpose of the out keyword in C#?	To pass arguments by reference and return multiple values	To declare a variable	To define a loop construct	To perform logical operations	To pass arguments by reference and return multiple values
22. Which of the following is NOT a valid C# data type modifier?	public	private	static	readonly	public
23. What is the purpose of the this keyword in C#?	To refer to the current instance of a class	To create an instance of a class	To define a loop construct	To compare two variables	To refer to the current instance of a class
24. Which keyword is used to handle the cleanup of unmanaged resources in C#?	using	dispose	cleanup	release	using
25. What is the purpose of the as operator in C#?	To perform type casting with safe conversion	To perform arithmetic calculations	To define a conditional statement	To exit a loop or switch statement	To perform type casting with safe conversion
26. Which of the following is NOT a valid C# access specifier?	public	private	protected	friendly	friendly
27. What is the purpose of the yield keyword in C#?	To create an iterator for a collection	To perform bitwise operations	To manage memory allocation for objects	To define a base class	To create an iterator for a collection
28. Which keyword is used to handle exceptional conditions in C#?	try	catch	throw	finally	throw
29. What is the purpose of the enum keyword in C#?	To define a set of named constants	To compare two variables	To perform logical operations	To define a loop construct	To define a set of named constants
30. Which of the following is NOT a valid C# control flow statement?	if-else	switch	for	while-else	while-else

Question	Option A	Option B	Option C	Option D	Answer
31. What is the purpose of the async and await keywords in C#?	To enable asynchronous programming and simplify handling of asynchronous tasks	To perform mathematical calculations	To define a loop construct	To compare two variables	To enable asynchronous programming and simplify handling of asynchronous tasks
32. Which of the following is NOT a valid C# access level?	public	private	protected	internal	internal
33. What is the purpose of the lambda expression in C#?	To create anonymous functions	To declare a variable	To perform logical operations	To define a loop construct	To create anonymous functions
34. Which keyword is used to perform early termination of a loop in C#?	break	exit	continue	return	break
35. What is the purpose of the nameof operator in C#?	To obtain the name of a variable, type, or member as a string	To perform arithmetic operations	To define a conditional statement	To iterate over elements in a collection or array	To obtain the name of a variable, type, or member as a string
36. Which of the following is NOT a valid C# exception handling block?	try	catch	finally	else	else
37. What is the purpose of the ref keyword in C#?	To pass arguments by reference	To create an instance of a class	To perform bitwise operations	To exit a loop or switch statement	To pass arguments by reference
38. Which keyword is used to create an abstract method in C#?	abstract	virtual	override	sealed	abstract
39. What is the purpose of the lock keyword in C#?	To synchronize access to shared resources in a multi-threaded environment	To compare two variables	To manage memory allocation for objects	To define a base class	To synchronize access to shared resources in a multi-threaded environment
40. Which of the following is NOT a valid C# data type?	int	float	decimal	number	number

Question	Option A	Option B	Option C	Option D	Answer
41. What is the purpose of the params keyword in C#?	To pass a variable number of arguments to a method	To declare a constant value	To define a loop construct	To perform logical operations	To pass a variable number of arguments to a method
42. Which of the following is NOT a valid C# access modifier?	public	private	protected	friendly	friendly
43. What is the purpose of the base keyword in C#?	To access members of the base class	To create an instance of a class	To define a conditional statement	To compare two variables	To access members of the base class
44. Which keyword is used to explicitly inherit an interface in C#?	implements	extends	inherits	interface	implements
45. What is the purpose of the default keyword in C#?	To initialize variables with their default values	To perform arithmetic calculations	To define a loop construct	To exit a loop or switch statement	To initialize variables with their default values
46. Which of the following is NOT a valid C# bitwise operator?	&	`	`	~	%
47. What is the purpose of the sealed keyword in C#?	To prevent a class from being inherited	To perform bitwise operations	To manage memory allocation for objects	To define a base class	To prevent a class from being inherited
48. Which keyword is used to specify a variable that cannot be modified in C#?	readonly	constant	immutable	static	readonly
49. What is the purpose of the nameof operator in C#?	To obtain the name of a variable, type, or member as a string	To compare two variables	To perform logical operations	To iterate over elements in a collection or array	To obtain the name of a variable, type, or member as a string
50. Which of the following is NOT a valid C# loop statement?	for	while	until	do-while	until

Question	Option A	Option B	Option C	Option D	Answer
51. What is the purpose of the using statement in C#?	To automatically release resources	To perform arithmetic calculations	To define a loop construct	To compare two variables	To automatically release resources
52. Which of the following is NOT a valid C# access modifier?	public	private	protected	friendly	friendly
53. What is the purpose of the static keyword in C#?	To define members that belong to the class itself, rather than instances of the class	To create an instance of a class	To define a conditional statement	To exit a loop or switch statement	To define members that belong to the class itself, rather than instances of the class
54. Which keyword is used to specify that a method overrides a base class method in C#?	override	virtual	new	base	override
55. What is the purpose of the checked keyword in C#?	To enable overflow checking for arithmetic operations	To perform bitwise operations	To manage memory allocation for objects	To define a base class	To enable overflow checking for arithmetic operations
56. Which of the following is NOT a valid C# logical operator?	&&	`		`	!
57. What is the purpose of the abstract keyword in C#?	To define a class that cannot be instantiated and can only be inherited	To compare two variables	To perform logical operations	To iterate over elements in a collection or array	To define a class that cannot be instantiated and can only be inherited
58. Which keyword is used to specify that a method can be overridden in a derived class in C#?	virtual	override	new	base	virtual
59. What is the purpose of the var keyword in C#?	To infer the type of a variable at compile time	To declare a constant value	To define a loop construct	To perform arithmetic calculations	To infer the type of a variable at compile time
60. Which of the following is NOT a valid C# relational operator?	==	!=	>	:=	:=

Question	Option A	Option B	Option C	Option D	Answer
61. What is the purpose of the readonly keyword in C#?	To declare a variable that can only be assigned a value at the time of declaration or in a constructor	To perform arithmetic calculations	To define a loop construct	To exit a loop or switch statement	To declare a variable that can only be assigned a value at the time of declaration or in a constructor
62. Which of the following is NOT a valid C# access modifier?	public	private	protected	friendly	friendly
63. What is the purpose of the delegate keyword in C#?	To define a reference type that can hold a method reference	To create an instance of a class	To define a conditional statement	To compare two variables	To define a reference type that can hold a method reference
64. Which keyword is used to specify that a method or class cannot be overridden or inherited in C#?	sealed	override	new	abstract	sealed
65. What is the purpose of the typeof operator in C#?	To obtain the type object of a specified type	To perform bitwise operations	To manage memory allocation for objects	To define a base class	To obtain the type object of a specified type
66. Which of the following is NOT a valid C# assignment operator?	=	+=	++	*=	++
67. What is the purpose of the interface keyword in C#?	To define a contract for implementing a set of methods and properties	To perform logical operations	To iterate over elements in a collection or array	To define a loop construct	To define a contract for implementing a set of methods and properties
68. Which keyword is used to specify that a method or class can be accessed without creating an instance in C#?	static	instance	dynamic	this	static
69. What is the purpose of the using directive in C#?	To import namespaces and enable the use of types without fully qualifying their names	To compare two variables	To perform arithmetic calculations	To define a loop construct	To import namespaces and enable the use of types without fully qualifying their names
70. Which of the following is NOT a valid C# conditional operator?	? :	??	!:	?.	!:

Question	Option A	Option B	Option C	Option D	Answer
71. What is the purpose of the try-catch block in C#?	To handle and catch exceptions	To perform arithmetic calculations	To define a loop construct	To compare two variables	To handle and catch exceptions
72. Which of the following is NOT a valid C# access modifier?	public	private	protected	friendly	friendly
73. What is the purpose of the out keyword in C#?	To pass a parameter by reference and allow the method to modify its value	To create an instance of a class	To define a conditional statement	To exit a loop or switch statement	To pass a parameter by reference and allow the method to modify its value
74. Which keyword is used to specify that a class cannot be instantiated in C#?	abstract	virtual	sealed	static	abstract
75. What is the purpose of the sizeof operator in C#?	To obtain the size in bytes of a value type	To perform bitwise operations	To manage memory allocation for objects	To define a base class	To obtain the size in bytes of a value type
76. Which of the following is NOT a valid C# unary operator?	++	--	!	~	~
77. What is the purpose of the partial keyword in C#?	To allow a class or struct to be defined in multiple source files	To compare two variables	To perform logical operations	To iterate over elements in a collection or array	To allow a class or struct to be defined in multiple source files
78. Which keyword is used to specify that a class member can be accessed by derived classes in C#?	protected	private	internal	base	protected
79. What is the purpose of the yield keyword in C#?	To define an iterator and generate a sequence of values	To perform arithmetic calculations	To define a loop construct	To exit a loop or switch statement	To define an iterator and generate a sequence of values
80. Which of the following is NOT a valid C# bitwise operator?	&	`	`	~	^

Question	Option A	Option B	Option C	Option D	Answer
81. What is the purpose of the nameof operator in C#?	To obtain the name of a variable, type, or member as a string	To perform arithmetic calculations	To define a loop construct	To compare two variables	To obtain the name of a variable, type, or member as a string
82. Which of the following is NOT a valid C# access modifier?	public	private	protected	friendly	friendly
83. What is the purpose of the ref keyword in C#?	To pass a parameter by reference and allow the method to modify its value	To create an instance of a class	To define a conditional statement	To exit a loop or switch statement	To pass a parameter by reference and allow the method to modify its value
84. Which keyword is used to specify that a class can be inherited in C#?	class	struct	sealed	base	class
85. What is the purpose of the as operator in C#?	To perform a safe type conversion or cast	To perform bitwise operations	To manage memory allocation for objects	To define a base class	To perform a safe type conversion or cast
86. Which of the following is NOT a valid C# logical operator?	&&	`		`	!
87. What is the purpose of the override keyword in C#?	To indicate that a method overrides a base class method	To compare two variables	To perform logical operations	To iterate over elements in a collection or array	To indicate that a method overrides a base class method
88. Which keyword is used to specify that a class member belongs to the instance of a class in C#?	this	static	dynamic	const	this
89. What is the purpose of the params keyword in C#?	To allow a variable number of arguments to be passed to a method	To define a constant value	To define a loop construct	To perform arithmetic calculations	To allow a variable number of arguments to be passed to a method
90. Which of the following is NOT a valid C# loop statement?	for	while	until	do-while	until

Question	Option A	Option B	Option C	Option D	Answer
91. What is the purpose of the lock keyword in C#?	To synchronize access to a shared resource	To perform arithmetic calculations	To define a loop construct	To compare two variables	To synchronize access to a shared resource
92. Which of the following is NOT a valid C# access modifier?	public	private	protected	internal	internal
93. What is the purpose of the params keyword in C#?	To allow a variable number of arguments to be passed to a method	To create an instance of a class	To define a conditional statement	To exit a loop or switch statement	To allow a variable number of arguments to be passed to a method
94. Which keyword is used to specify that a class cannot be inherited in C#?	sealed	override	abstract	virtual	sealed
95. What is the purpose of the typeof operator in C#?	To obtain the type object of a specified type	To perform bitwise operations	To manage memory allocation for objects	To define a base class	To obtain the type object of a specified type
96. Which of the following is NOT a valid C# relational operator?	==	!=	>	<>	<>
97. What is the purpose of the async keyword in C#?	To define an asynchronous method that can be awaited	To compare two variables	To perform logical operations	To iterate over elements in a collection or array	To define an asynchronous method that can be awaited
98. Which keyword is used to specify that a class member can only be accessed within the same assembly in C#?	internal	protected	private	base	internal
99. What is the purpose of the using directive in C#?	To import namespaces and enable the use of types without fully qualifying their names	To perform arithmetic calculations	To define a loop construct	To exit a loop or switch statement	To import namespaces and enable the use of types without fully qualifying their names
100. Which of the following is NOT a valid C# bitwise operator?	&	`	`	~	^