Method Overloading in Java

1) What is Method?

• In Java, a method is a block of code that performs a specific task and only runs when it is called.

• Methods are used to define the behavior of objects and classes, allowing you to reuse code without retyping it.

• Java categorizes methods into two primary types:

Predefined (Standard Library) Methods: Built-in methods provided by Java libraries, such as System.out.println() or Math.sqrt().

User-defined Methods: Custom blocks of code written by programmers to solve specific problems.

2) What is Method Overloading?

• Method overloading in Java is a feature that allows a class to have multiple methods with the same name, provided they have different parameter lists.

• It is a form of compile-time polymorphism (also known as static binding), where the Java compiler determines which method to call based on the arguments provided.

3) Core Rules for Overloading

To successfully overload a method, the method signature (name + parameters) must be unique. Methods can be overloaded by changing:

• Number of Parameters: For example, add(int a, int b) and add(int a, int b, int c).

• Data Types of Parameters: For example, display(int a) and display(String a).

• Order of Parameters: For example, process(int a, String b) and process(String b, int a).

Example:

public class Calc {

    public static void main(String[] args) {
        Calc obj = new Calc();

        System.out.println(obj.add(10, 20));        // Method 1
        System.out.println(obj.add(10, 20, 30));    // Method 2
        System.out.println(obj.add(10.5, 20.5));    // Method 3
    }

    // Method 1: Two integers
    public int add(int a, int b) {
        return a + b;
    }

    // Method 2: Three integers
    public int add(int a, int b, int c) {
        return a + b + c;
    }

    // Method 3: Double values
    public double add(double a, double b) {
        return a + b;
    }
}

Output: