Learn C# .Net MCQs
Prepare C# .Net MCQs (Multiple choice Questions) for exam and job interviews.
Which of the following is true about the "readonly" keyword in C#?
1) It allows modification only in the constructor.
2) It allows modification anywhere in the class.
3) It cannot be modified.
4) None of the above
Answer : It allows modification only in the constructor.
What is the output of Console.WriteLine(5 == 5);?
1) true
2) false
3) Error
4) None of the above
Answer : true
Which of the following is used to define an enum in C#?
1) enum
2) enumType
3) Enum
4) None of the above
Answer : enum
Which of the following is true about a finalizer in C#?
1) It is called automatically when the object is destroyed.
2) It is called manually.
3) It has parameters.
4) None of the above
Answer : It is called automatically when the object is destroyed.
Which of the following is the correct way to declare a nullable value type in C#?
1) int? num;
2) nullable int num;
3) int num = null;
4) None of the above
Answer : int? num;
What is the output of Console.WriteLine("Hello".Substring(0, 3));?
1) Hel
2) lo
3) Error
4) None of the above
Answer : Hel
Which of the following is used to define an extension method in C#?
1) this
2) new
3) extension
4) None of the above
Answer : this
Which of the following is used to check if an object is null in C#?
1) == null
2) isNull()
3) is null
4) None of the above
Answer : == null
What is the output of Console.WriteLine(Math.Round(5.5));?
1) 6
2) 5
3) 5.5
4) Error
Answer : 6
Which of the following is true about delegates in C#?
1) They are type-safe.
2) They are not type-safe.
3) They are only used for events.
4) None of the above
Answer : They are type-safe.