Method in Java

A method is a block of code designed to perform a specific task. Methods are executed only when they are called, making programs more structured, reusable, and easier to maintain.

What is a Method?

A method is similar to a function in other programming languages. It groups a set of statements together to perform an operation.

class Test {

    static void greet() {
        System.out.println("Hello, Java!");
    }

    public static void main(String[] args) {
        greet();  // method call
    }
}

Execution Flow

• The program starts from the main() method
• greet() method is called
• The message is printed

Method Overloading

Method Overloading is a feature in Java where multiple methods share the same name but differ in their parameters. It is an example of compile-time polymorphism.

Method overloading means:

• Same method name
• Different parameter list (type, number, or order)

Different Number of Parameters

class Test {

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

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

    public static void main(String[] args) {
        System.out.println(add(2, 3));      // 2 params
        System.out.println(add(2, 3, 4));   // 3 params
    }
}

Different Data Types

class Test {

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

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

    public static void main(String[] args) {
        System.out.println(add(5, 10));        // int
        System.out.println(add(5.5, 2.5));     // double
    }
}

Different Order of Parameters

class Test {

    static void display(int a, String b) {
        System.out.println(a + " " + b);
    }

    static void display(String b, int a) {
        System.out.println(b + " " + a);
    }
}

Important Rules

✔ Must Change Parameter List
Overloading works only if parameters differ in:

• Number
• Data type
• Order

Same name + same parameters + different return → ERROR

int add(int a, int b) { return a + b; }

//  Error (same parameters)
double add(int a, int b) { return a + b; }

Why Use Method Overloading?

• Improves code readability
• Reduces method name complexity
• Reuse same method name for similar operations

Example

System.out.println(10);
System.out.println("Hello");
System.out.println(3.14);

println() is overloaded to handle different data types.

At compile time, Java decides:

• Which method to call based on arguments
• This is called compile-time polymorphism

Summary

• Same method name
• Different parameters
• Compile-time decision
• Improves flexibility and readability