// Base classclass Animal {    public void makeSound() {        System.out.println("Animal makes a sound");    }}// Subclassesclass Dog extends Animal {    @Override    public void makeSound() {        System.out.println("Dog barks");    }}class Cat extends Animal {    @Override    public void makeSound() {        System.out.println("Cat meows");    }}// Runtime polymorphismAnimal animal1 = new Dog();Animal animal2 = new Cat();animal1.makeSound(); // "Dog barks" - calls Dog's methodanimal2.makeSound(); // "Cat meows" - calls Cat's method// Polymorphic arrayAnimal[] animals = {new Dog(), new Cat(), new Animal()};for (Animal animal : animals) {    animal.makeSound(); // Calls appropriate method for each}// Compile-time polymorphism (Method Overloading)class Calculator {    public int add(int a, int b) {        return a + b;    }        public double add(double a, double b) {        return a + b;    }        public int add(int a, int b, int c) {        return a + b + c;    }}Calculator calc = new Calculator();int sum1 = calc.add(5, 3);        // Calls int versiondouble sum2 = calc.add(5.5, 3.2); // Calls double versionint sum3 = calc.add(1, 2, 3);     // Calls three-parameter version// Interface polymorphisminterface Shape {    double area();}class Circle implements Shape {    private double radius;        public Circle(double radius) {        this.radius = radius;    }        @Override    public double area() {        return Math.PI * radius * radius;    }}class Rectangle implements Shape {    private double width, height;        public Rectangle(double width, double height) {        this.width = width;        this.height = height;    }        @Override    public double area() {        return width * height;    }}// Polymorphic usageShape[] shapes = {    new Circle(5.0),    new Rectangle(4.0, 6.0)};for (Shape shape : shapes) {    System.out.println("Area: " + shape.area());}