Method Return Values in C#

Methods Return Values in C#

Learn how methods return values using the return keyword with practical C# examples.

Table of Contents

1. What is a Return Value?
2. Why Return Values?
3. Syntax
4. Examples
5. Common Mistakes
6. Best Practices
7. Summary

What is a Return Value?

A return value is the result that a method sends back to the code that called it. The return keyword ends the method execution and returns a value.

Note: A method with a return type must always return a value of the correct type.

Method Syntax

returnType MethodName(parameters)
{
    return value;
}

Method Returning an Integer

static int Add(int a, int b)
{
    return a + b;
}

int result = Add(10, 20);
Console.WriteLine(result);

Method Returning a String

static string GetMessage()
{
    return "Welcome to C#";
}

Console.WriteLine(GetMessage());

Method Returning a Boolean

static bool IsAdult(int age)
{
    return age >= 18;
}

Console.WriteLine(IsAdult(25));

Using Returned Values

int total = Add(15,25);

if(total > 30)
{
    Console.WriteLine("Total is greater than 30");
}

Tip: Return values make methods reusable because the caller decides how to use the returned data.

Complete Example

using System;

class Program
{
    static double CalculateArea(double radius)
    {
        return 3.14 * radius * radius;
    }

    static void Main()
    {
        double area = CalculateArea(5);
        Console.WriteLine("Area = " + area);
    }
}

Output

Area = 78.5

Common Mistake: Don't forget to return a value from methods whose return type is not void.

void vs Return Value

void Method	Method with Return Value
Does not return any value.	Returns a value to the caller.
Used for actions like printing.	Used for calculations and results.

Best Practices

• Return meaningful values.
• Keep methods focused on one task.
• Use the correct return type.
• Avoid unreachable code after return.

Summary

Concept	Description
return	Ends a method and returns a value.
void	No value returned.
Return Type	Specifies the type of returned value.

Interview Questions

1. What is a return value?
2. Difference between void and int methods?
3. Can a method return a string?
4. What happens if a non-void method doesn't return a value?

Practice Exercise

• Create a method that returns the square of a number.
• Create a method returning the maximum of two numbers.
• Create a method returning true if a number is even.

FAQ

Can a method return different data types?
Each method returns only one declared return type, but you can create different methods with different return types.

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