Method Overloading in C#

Learn how to create multiple methods with the same name but different parameters in C#.

Table of Contents

1. What is Method Overloading?
2. Why Use Method Overloading?
3. Rules
4. Examples
5. Best Practices
6. Summary

What is Method Overloading?

Method overloading allows multiple methods to have the same name, provided they have different parameter lists. The compiler decides which method to call based on the number, type, or order of parameters.

Note: Method overloading is an example of compile-time polymorphism.

Why Use Method Overloading?

• Improves code readability.
• Reduces the need for multiple method names.
• Allows the same operation to work with different inputs.

Simple Example

static void Display()
{
    Console.WriteLine("Hello");
}

static void Display(string name)
{
    Console.WriteLine("Hello " + name);
}

Overloading with Different Number of Parameters

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

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

Overloading with Different Data Types

static int Multiply(int a, int b)
{
    return a * b;
}

static double Multiply(double a, double b)
{
    return a * b;
}

Tip: Use overloading when methods perform the same logical task but accept different input types.

Rules for Method Overloading

Allowed	Not Allowed
Different number of parameters	Changing only the return type
Different parameter types	Same parameter list with same types
Different parameter order (different types)	Duplicate method signatures

Common Mistake: You cannot overload a method by changing only its return type. The parameter list must be different.

Complete Example

using System;

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

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

    static void Main()
    {
        Console.WriteLine(Add(10,20));
        Console.WriteLine(Add(5.5,2.5));
    }
}

Output

30
8

Best Practices

• Keep overloaded methods related to the same task.
• Use meaningful parameter names.
• Avoid creating too many overloads that confuse users.
• Document each overload clearly.

Summary

Concept	Description
Method Overloading	Same method name with different parameters.
Compile-time Polymorphism	Method selected during compilation.
Return Type	Cannot overload by return type alone.

Interview Questions

1. What is method overloading?
2. Can methods be overloaded using only the return type?
3. What is compile-time polymorphism?
4. What are the rules of method overloading?

Practice Exercise

• Create overloaded methods to calculate the area of a square and rectangle.
• Create overloaded methods for displaying employee details.
• Overload a method using int and double parameters.

FAQ

Can constructors be overloaded?
Yes. Constructors can also be overloaded.

Can static methods be overloaded?
Yes. Static methods support method overloading.

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