Method Overloading in JAVA - Compile-time Polymorphism

#java #oop #programming #beginners

Method Overloading :

Method overloading allows a class to have multiple methods with the same name but different parameter lists.
It is an example of Compile-Time Polymorphism (also called Static Polymorphism).
The compiler determines which method to call based on the arguments provided.
Overloading works within the same class or in subclasses

Rules for Method Overloading :

Number of parameters.
Type of parameters.
Order of parameters.
You cannot overload by changing only return type.

Change the Number of parameters :

class Product {
    public int multiply(int a, int b) {
        return a * b;
    }
    public int multiply(int a, int b, int c) {
        return a * b * c;
    }
}

Change the Type of parameters :

class Display {
    void show(int a) {
        System.out.println("Integer: " + a);
    }
    void show(String s) {
        System.out.println("String: " + s);
    }
}

Change the Order of parameters :

class Example {
    void print(int a, String b) { }
    void print(String b, int a) { }
}

Invalid Overloading (Only Return Type Changed)

class Test {

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

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

Compiler error because parameters are the same.