Polymorphism in java

#polymorphism #java #fullstack #programming

Polymorphism in Java is one of the core concepts in object-oriented programming (OOP) that allows objects to behave differently based on their specific class type.
The word polymorphism means having many forms, and it comes from the Greek words poly (many) and morph (forms), this means one entity can take many forms.

Real-Life Illustration of Polymorphism

Consider a person who plays different roles in life, like a father, a husband, and an employee. Each of these roles defines different behaviors of the person depending on the object calling it.

Types of Polymorphism

Compile-time Polymorphism (Method Overloading):

Achieved by defining multiple methods with the same name but different parameters within the same class.


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

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

    public static void main(String[] args) {
        OverloadingExample obj = new OverloadingExample();
        System.out.println("Sum of integers: " + obj.add(5, 10));
        System.out.println("Sum of doubles: " + obj.add(5.5, 10.5));
    }
}

Runtime Polymorphism (Method Overriding):

Achieved when a subclass provides a specific implementation of a method already defined in its superclass.


class Animal {
    public void sound() {
        System.out.println("Animal makes a sound");
    }
}

class Dog extends Animal {
    @Override
    public void sound() {
        System.out.println("Dog barks");
    }
}

public class OverridingExample {
    public static void main(String[] args) {
        Animal myAnimal = new Dog();
        myAnimal.sound(); // Outputs "Dog barks"
    }
}