Master C# Programming From Scratch

Method Overloading in C#

What is Method Overloading?

Method Overloading is a feature in C# that allows a class to have multiple methods with the same name but with different parameters.

The overloaded methods can have different numbers of parameters, different parameter types, or different parameter arrangements. The compiler determines which method should be called based on the arguments passed to the method.

Why Use Method Overloading?

• Improves code readability.
• Allows the same logical operation to use one meaningful method name.
• Reduces the need for multiple differently named methods.
• Provides flexibility when working with different types or numbers of inputs.
• Supports compile-time polymorphism.

Rules of Method Overloading

To overload a method, the methods must have the same method name but differ in their parameter list.

• Different number of parameters.
• Different parameter data types.
• Different order of parameter types.

1. Overloading by Number of Parameters

We can create multiple methods with the same name but different numbers of parameters.

Example

using System;
class Calculator
{
    static int Add(int a, int b)
    {
        return a + b;
    }

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

Console.WriteLine(Calculator.Add(10, 20));
Console.WriteLine(Calculator.Add(10, 20, 30));

using System;
 
class Calculator
{
    static int Add(int a, int b)
    {
        return a + b;
    }

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

Console.WriteLine(Calculator.Add(10, 20));
Console.WriteLine(Calculator.Add(10.5, 20.5));

using System;
 
class Display
{
    static void Show(string name, int age)
    {
        Console.WriteLine($"Name: {name}, Age: {age}");
    }

    static void Show(int age, string name)
    {
        Console.WriteLine($"Age: {age}, Name: {name}");
    }
}

Display.Show("Rahul", 25);
Display.Show(25, "Rahul");

using System;
 
class Printer
{
    static void Print(int number)
    {
        Console.WriteLine($"Number: {number}");
    }

    static void Print(string text)
    {
        Console.WriteLine($"Text: {text}");
    }
}

Printer.Print(100);
Printer.Print("Hello");

// Invalid

static int Calculate(int a)
{
    return a;
}

static double Calculate(int a)
{
    return a;
}

using System;
 
class Student
{
    public string Name;
    public int Age;

    public Student()
    {
        Name = "Unknown";
        Age = 0;
    }

    public Student(string name)
    {
        Name = name;
    }

    public Student(string name, int age)
    {
        Name = name;
        Age = age;
    }
}

Student student1 = new Student();
Student student2 = new Student("Rahul");
Student student3 = new Student("Priya", 22);

using System;
 
class Payment
{
    public void ProcessPayment(double amount)
    {
        Console.WriteLine($"Processing payment of ₹{amount}");
    }

    public void ProcessPayment(double amount, string cardNumber)
    {
        Console.WriteLine(
            $"Processing ₹{amount} using card {cardNumber}");
    }

    public void ProcessPayment(double amount, string cardNumber, string currency)
    {
        Console.WriteLine(
            $"Processing {currency} {amount} using card {cardNumber}");
    }
}

Payment payment = new Payment();

payment.ProcessPayment(1000);
payment.ProcessPayment(1000, "XXXX-1234");
payment.ProcessPayment(1000, "XXXX-1234", "INR");