Learn C# .Net MCQs

Prepare C# .Net MCQs (Multiple choice Questions) for exam and job interviews.

Which of the following is a valid way to declare a constant in C#?

1) const int x = 5;

2) readonly int x;

3) int x = 5;

4) None of the above

Answer : const int x = 5;

What is the output of Console.WriteLine(2 * 3 + 1);?

1) 7

2) 6

3) Error

4) None of the above

Answer : 7

Which of the following can be used to serialize an object in C#?

1) BinaryFormatter

2) JsonSerializer

3) XmlSerializer

4) All of the above

Answer : All of the above

Which of the following is used to iterate over a collection in C#?

1) foreach

2) for

3) while

4) do-while

Answer : foreach

What does the "var" keyword do in C#?

1) Declares a variable with a specific type

2) Infers the type of a variable

3) Defines a method

4) None of the above

Answer : Infers the type of a variable

Which of the following statements is true about interfaces in C#?

1) They can contain implementation.

2) They can only have method signatures.

3) They can inherit from classes.

4) None of the above

Answer : They can only have method signatures.

What is the output of Console.WriteLine(5 == 5 && 4 > 2);?

1) true

2) false

3) Error

4) None of the above

Answer : true

Which of the following is NOT a C# access modifier?

1) internal

2) private

3) protected

4) global

Answer : global

What is the output of Console.WriteLine(10 % 3);?

1) 1

2) 3

3) 2

4) Error

Answer : 1

Which of the following types can be used as a nullable type in C#?

1) int?

2) string?

3) double?

4) All of the above

Answer : All of the above