Learn C# .Net MCQs

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

Which of the following is a collection type that allows duplicate elements in C#?

1) HashSet

2) List

3) Dictionary

4) None of the above

Answer : List

What is the output of Console.WriteLine("a" == "A");?

1) true

2) false

3) Error

4) None of the above

Answer : false

Which of the following is used to implement an interface in C#?

1) class MyClass : IMyInterface {}

2) class MyClass implements IMyInterface {}

3) class MyClass extends IMyInterface {}

4) None of the above

Answer : class MyClass : IMyInterface {}

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

1) 7

2) 8

3) 6

4) None of the above

Answer : 7

What is the purpose of the "lock" keyword in C#?

1) To prevent multiple threads from accessing a block of code.

2) To define a method that can be executed in parallel.

3) To create a mutex.

4) None of the above

Answer : To prevent multiple threads from accessing a block of code.

Which of the following is the correct way to comment a single line in C#?

1) // comment

2) # comment

3) /* comment */

4) None of the above

Answer : // comment

What is the output of Console.WriteLine(4 + 5 - 3);?

1) 6

2) 5

3) Error

4) None of the above

Answer : 6

Which keyword is used to handle exceptions in C#?

1) try

2) catch

3) finally

4) None of the above

Answer : catch

What is the output of Console.WriteLine("Hello".StartsWith("H"));?

1) true

2) false

3) Error

4) None of the above

Answer : true

Which of the following is the correct syntax to declare an array in C#?

1) int[] arr;

2) int arr[];

3) arr int[];

4) None of the above

Answer : int[] arr;