Return values and void methods in C Sharp (C#) - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a return value in a method?

A return value is the result a method sends back to the part of the program that called it. It can be a number, text, or any data type.

beginner

What does a void method mean in C#?

A void method does not return any value. It just runs some code and finishes without sending anything back.

beginner

How do you return a value from a method in C#?

Use the return keyword followed by the value you want to send back. For example: return 5;

intermediate

Can a method have both void and return a value?

No. A method declared as void cannot return a value. If it returns a value, it must have a matching return type.

intermediate

What happens if a method with a return type does not have a return statement?

The program will give a compile-time error because it expects a value to be returned from the method.

What keyword do you use to send a value back from a method?

A return

B send

C output

D yield

The return keyword is used to send a value back from a method.

What type of method does NOT return any value?

A bool

B string

C int

D void

A void method does not return any value.

Which of these is a valid method header for a method that returns a number?

A int GetNumber()

B void GetNumber()

C void GetNumber(int number)

D string GetNumber()

The method int GetNumber() returns an integer number.

What will happen if a method declared to return int does not have a return statement?

A It will return 0 automatically

B It will cause a compile-time error

C It will return null

D It will run but return garbage value

Methods with a return type must have a return statement; otherwise, the compiler shows an error.

Can a void method use the return keyword?

A No, never

B Yes, with a value

C Yes, but only without a value

D Only in constructors

A void method can use return; to exit early but cannot return a value.

Explain the difference between a method that returns a value and a void method.

Think about whether the method sends something back or just runs code.

Describe what happens if you forget to include a return statement in a method that should return a value.

What does the compiler expect from methods with return types?