Define polymorphism. Differentiate between overloading and overriding method with example.

 Polymorphism is a concept in object-oriented programming that allows objects of different classes to be treated as if they were objects of the same class. It allows a single method or operation to have different meanings or behaviors based on the context in which it is used.

In Java, there are two types of polymorphism:

• Compile-time Polymorphism: This is achieved through method overloading, where two or more methods in a class have the same name but different parameters.
• Runtime Polymorphism: This is achieved through method overriding, where a subclass provides its own implementation of a method that is already defined in its parent class.

Here is an example of method overloading:

class MyClass {
   public int sum(int a, int b) {
      return a + b;
   }
   public double sum(double a, double b) {
      return a + b;
   }
}
public class Main {
   public static void main(String[] args) {
      MyClass obj = new MyClass();
      System.out.println(obj.sum(5, 10));
      System.out.println(obj.sum(5.5, 10.5));
   }
}

In this example, we define a class MyClass with two methods named sum() that have the same name but different parameter types (int and double). We create an object of MyClass and call both sum() methods with different arguments. The output of the program will be:

15
16.0

Here is an example of method overriding:

class Animal {
   public void makeSound() {
      System.out.println("The animal makes a sound");
   }
}
class Dog extends Animal {
   public void makeSound() {
      System.out.println("The dog barks");
   }
}
public class Main {
   public static void main(String[] args) {
      Animal animal = new Animal();
      animal.makeSound();
      Dog dog = new Dog();
      dog.makeSound();
   }
}

In this example, we define a class Animal with a method named makeSound(), and a subclass Dog that overrides the makeSound() method with its own implementation. We create objects of both Animal and Dog classes and call the makeSound() method on each object. The output of the program will be:

The animal makes a sound
The dog barks

This shows that the makeSound() method is behaving differently based on the type of object that is calling it. This is an example of runtime polymorphism achieved through method overriding.