Question: Explain the concepts of inheritance and polymorphism in object-oriented programming. Provide an example in Java to demonstrate inheritance and polymorphism, and explain how the program exhibits these two concepts in action.

Answer: Inheritance and polymorphism are two fundamental concepts in object-oriented programming. Inheritance allows a class to inherit properties and behaviors from another class, while polymorphism allows objects to be treated as instances of their parent class.

Inheritance:

Inheritance enables a new class to take on the properties and methods of an existing class. This promotes code reusability and allows for the creation of a hierarchy of classes with shared characteristics.

Polymorphism:

Polymorphism allows objects of different classes to be treated as objects of a common parent class. This allows for flexibility in the design and implementation of object-oriented systems.

Example in Java:

// Parent class
class Animal {
    public void makeSound() {
        System.out.println("Some generic sound");
    }
}

// Child class inheriting from Animal
class Dog extends Animal {
    @Override
    public void makeSound() {
        System.out.println("Woof woof!");
  }
}

public class Main {
    public static void main(String[] args) {
        Animal myDog = new Dog();
        myDog.makeSound(); // Output: Woof woof!
    }
}

Explanation: In the given example, the Animal class serves as the parent class, and the Dog class inherits from the Animal class. The makeSound method is overridden in the Dog class, demonstrating inheritance.

The Main class demonstrates polymorphism by creating an instance of the Dog class and assigning it to a variable of type Animal. Despite the variable being of type Animal, it is able to call the makeSound method of the Dog class, illustrating polymorphic behavior.

This code illustrates inheritance and polymorphism in action, as the Dog class inherits the makeSound method from the Animal class and exhibits polymorphic behavior when assigned to a variable of type Animal.