Top 100 C# Interview Questions and Answers 2023

C# is one of the well-known programming languages. It is used in the development of web, desktop and mobile applications. It is the preferred language for .NET development. C# is one of the best general-purpose object-oriented programming languages. This language is developed by Microsoft. It is recognized by International Standards Organization (ISO) and European Computer Manufacturers Association (ECMA). The feature like high scalability, faster development time and gentle learning curve makes it a very popular language in the scene of software development. It is versatile and flexible. If you are a job seeker preparing for interviews, questions during the interviews can be a bit overwhelming even when you are proficient in C#. So, we are providing the Top 100 of C# Interview Questions and Answers 2023 in this blog so that you will be well-prepared for the upcoming interviews.

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Top 100 of C# Interview Questions and Answers 2023

1. What is C#?

This is one of the chief C# Interview Questions and Answers. C# is one of the object-oriented programming languages developed by the firm Microsoft. It is used for building applications that run on the .NET framework.

2. Name the Data-types in C#.

There are two varieties of data types in C#. They are the value type and the reference type.

3. C# Uses What Kind of Syntax for Declaring A Variable?

The syntax used by C# is ‘type variableName = value;

4. Name the Five Access Modifiers in C#.

  • Public
  • Private
  • Protected
  • Internal
  • protected internal

5. What is CLR?

Common Language Runtime architecture manages the execution of programs in different languages. It also takes on tasks like memory management, security management, garbage collection etc.

6. Is There A Difference Between Value Type And Reference Type?

Yes. Value type holds a value directly while a reference type holds a reference to an object.

7. How Is Exception Handled In C#?

Try-catch-finally blocks are used for handling exceptions in C#?

8. What Is Object Oriented Programming?

An object-oriented program organizes a program using objects and classes.

9. What Syntax Is Used To Define A Method In C#?

The syntax is “accessModifier returnType methodName (parameters) { // method body }”.

10. What Is The Keyword Used For Achieving Inheritance In C#?

“Extends” is the keyword used for achieving inheritance in C#.

11. Name The Types Of Loops In C#.

For, while, and do-while are the three types of loops in C#.

12. What Is Polymorphism?

Polymorphism is a concept of object-oriented programming in which objects of different classes are treated as belonging to the same type.

13. Explain Encapsulation in C#.

Hiding the implementation details of an object from the external world is called Encapsulation in C#.

14. Differentiate Between Delegate And An Event?

Delegate is a type that denotes a method signature whereas an event is a mechanism for sending notifications.

15. Give The Syntax For Making Class In C#?

The syntax is “accessModifier class ClassName { // class members }”.

16. Define Abstraction in C#.

Hiding implementation details while only showing necessary information to the user is called abstraction.

17. State The Use Of While Loop?

A while loop executes a block of code repetitively as long as a specific condition is true.

18. Give The Use Of For Loop?

A for loop is used for iterating over a series of values.

19. Define a Lambda Expression in C#?

It is a brief way of representing an anonymous method in C#.

20. Give The Syntax For Making A Constructor In C#.

The syntax is “ accessModifier ClassName (parameters) { // constructor body } ”.

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21. Define A Thread In C#.

An unconnected path of execution that runs alongside the main program is called a thread.

22. How Does Thread In C# Help In Improving Program Performance?

By multitasking and parallel processing.

23. Define a Lock in C#.

The synchronisation mechanism that helps in preventing numerous threads from accessing a shared resource simultaneously is called a lock.

24. What Is The Type Of Strut?

Value type

25. Give the Use of Namespace In C#.

It is a method of organising code in C# language. It also provides a hierarchical structure that is needed for grouping types that are related. It also helps in avoiding naming conflicts that occur between different code elements.

26. What Is The Type Of Class?

Reference type

27. Give The Syntax For Creating A For Loop In C#?

The syntax is “ for (initialization; condition; increment) { // loop body } ”.

28. Define the Constructor in C#.

It is a special method that is utilized for the initialization of objects in C#.

29. The Access Modifier Of A Static Constructor In C# Should Be?


30. Give The Syntax That Is Used For Creating A Switch Statement In C#?

switch (expression) { case value1: // statement(s); break; case value2: // statement(s); break; default: // statement(s); break; }

31. State The Syntax Of Keyword Override In C#.

override <member-declaration>

32. Give The Syntax Of Keyword New In C#?

new <member-declaration>

33. Define An Abstract Class In C#.

A class in C# that cannot be instantiated is called an abstract class.

34. Name The Class In C# That Cannot Be Inherited From?

Sealed class

35. Name the Class In C# That Is Split Into Multiple Files?

Partial class

36. Which Is The Class Which Can Operate On Multiple Data Types Without The Need To Be Rewritten For Each Type?

Generic class

37. Try Catch Block Can Be Created Using Which Syntax?

try { // statement(s); } catch (ExceptionType e) { // statement(s); }

38. State The Use Of Generic Method In C#?

They are used for developing reusable algorithms and functions.

39. Define “==” Operator.

It is a binary operator that is used for comparing the values of two objects or variables.

40. Explain the “Equals ()” Method.

It is a method that is utilized for comparing the values of two objects or variables.

41. Which is a member of a class that offers a way to read or write a private field in a regulated manner?


42. State The Uses Of Get Accessor In C#.

It is utilized for retrieving the value of a property.

43. Give the Syntax for Creating a While Loop.

while (condition) { // loop body }

44. State The Use Of A Set Accessor.

It is utilized for setting the value of a property.

45. Explain An Event?

It is the way by which an object notifies other objects that something happened.

46. What Is A Group Of Related Objects Called In C#?


47. Define An Array In C#.

The array is a data structure in C#.  It stores a permanent size successive collection of elements of the same type.

48. Explain a string.

A series of characters that denotes text is called a string.

49. Define a StringBuilder?

It is a mutable string which can be modified without the creation of a new object.

50. What Is Collection That Stores Key-Value Pairs In C# Called?


51. What Is Collection That Stores An Ordered Sequence Of Elements Called?


52. Give The Syntax For The Creation Of A Do-While Loop In C#.

do { // loop body } while (condition);

53. What is Tuple?

It is a data structure. It contains a fixed number of elements. Each of the elements may belong to different types.

54. What Is a Type That Can Be Also Assigned A Null Value Called?

Nullable type

55. Give Example Of Value Types.

int, float, bool, and struct

56. What Principle Is The Basis Of The Working Of Stacks?

Last-In-First-Out (LIFO) principle

57. What Does Last-In-First-Out (LIFO) Principle Mean?

This means that the element which was added last will be the one that is to be removed first.

58. Give The Syntax Of Lock?

lock (object) { … }

59. Give The Syntax Of The Monitor?

Monitor.Enter(object); … Monitor.Exit(object);

60. Name A Few Common Operations Performed On A Stack.

Push, pop, peek, count and clear.

61. Name A Few Common Operations Performed On A Queue.

Enqueue, dequeue, peek, count and clear.

62.What Principle Does Queue Follow?

First-In-First-Out (FIFO) principle.

63. What Does First-In-First-Out (FIFO) Principle Mean?

This means that the element which was added first will be the one that is to be removed first.

64. Give The Syntax For Creating An If-Else Statement.

if (condition) { // statement(s); } else { // statement(s); }

65. Define a HashSet.

A collection in C# that stores unique elements is known as HashSet.

66. Define an IDictionary.

An interface in C# that denotes a collection of key-value pairs is called IDictionary.

67. Give The Syntax For Foreach?

foreach (var <variable> in <collection>) { <statements> }

68. Give the Syntax Of For?

for (<initializer>; <condition>; <increment>) { <statements> }

69. Define an IEnumerator?

An interface is C# that offers a way to iterate over a collection of elements.

70. Define an IEnumerable.

An interface if C# denotes a collection of elements that can be enumerated.

71. What Do We Call A Group Of Delegates That We Call On To Perform A Particular Action?

Delegate chain

72. What Is Used For Combining Multiple Delegates To Make A Single Delegate?

“+” operator

73. Which Method Has No Name As Well As Is Defined Inline with the Rest of the Code?

Anonymous method

74. In Which Version Was the Anonymous Method Introduced?

C# 2.0

75. What Is Delegate With Multiple Methods Assigned To It Called?

Multicast delegate

76. In Which Order Is Multicast Delegate Called?

They are called in the order they were added.

77. What Is The Use Of Covariance?

It is a feature that permits the complete conversion of a derived class to its base class.

78. What Is A Directive Statement That Is Processed Before The Code Is Compiled Called?

Pre-processor directive

79. Which is the symbol with which a Pre-processor directive begins?


80. State The Use Of #Define Directive?

It is utilized for defining a symbol or constant that can be utilized through the program.

81. State the Use of #If Directive?

It is utilized for conditionally compiling code on the basis of the value of a symbol or constant.

82. Give The Use Of #Endif Directive?

It marks the termination of a conditional compilation block in C#.

83. What Is the Use of #Else Directive?

It is utilised in conjunction with the “#if directive” to make alternative code blocks.

84. State Uses of #Elif Directive?

It is utilised for testing additional conditions afterwards an initial #if directive

85. Give The Use Of #Warning Directive?

It is utilised for issuing a warning message during compilation.

86. What Is The Use Of #Error Directive?

The use of this tool is the generation of a compiler error during compilation.

87. What Is The Class That Is Utilised To Convert Values Between Various Data Types?

Type Converter

88. What Is Used For Converting An Object To Its String Depiction?

ToString() method

89. What Generates A Hash Code For An Object?

GetHashCode() method

90. State the Use of Equals () Method?

It is utilised for comparing two objects for equality.

91. Give The Use Of Gettype() Method?

It gives the runtime type of an object.

92. Which Operator Is Used For Checking If An Object Is Of A Given Type?

Is operator

93. Which Operator Gives The Default Value Of A Given Type?

Default operator

94. State The Use Of Ref Keyword?

It is utilized for passing a variable by reference to a method.

95. What Is Used For Specifying A Variable Number Of Arguments To A Method?

Params keyword

96. What Is Used For The Creation Of An Iterator Method?

Yield keyword

97. What Is A Contract That Defines A Set Of Methods And Properties That Must Be Implemented By A Class Called?


98. State Uses of Var?

It is utilized in declaring a variable whose type is inferred by the compiler at the compile time.

99. What Does A Resource File Contain?

It has data that can be accessed and utilized by an application

100. What Is The Use Of Dynamic?

It is utilized in declaring a variable whose type is determined at the runtime.

The questions and answers provided here will help you ace your interview and achieve your dream of becoming a .NET developer.

C# Interview Questions and Answers FAQs

1. What is the field in which C# is majorly used?

.NET development

2. Which firm developed the C# language?


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