Multilevel Inheritance – Method Overriding

Multilevel inheritance and method overriding are two important concepts in object-oriented programming, especially in Java. Let's discuss each of them:

Multilevel Inheritance:

Multilevel inheritance refers to a scenario where a derived class inherits properties and behavior from a base class, and another class then inherits from this derived class. This creates a chain of inheritance, where each class inherits from the one preceding it.

For example:

class Animal {

    void eat() {

        System.out.println("Animal is eating");

    }

}

class Dog extends Animal {

    void bark() {

        System.out.println("Dog is barking");

    }

}

class Labrador extends Dog {

    void color() {

        System.out.println("Labrador is golden in color");

    }

}

public class Main {

    public static void main(String[] args) {

        Labrador labrador = new Labrador();

        labrador.eat();   // Inherited from Animal

        labrador.bark();  // Inherited from Dog

        labrador.color(); // Specific to Labrador

    }

}

In this example, the `Labrador` class inherits from the `Dog` class, which in turn inherits from the `Animal` class. This demonstrates multilevel inheritance.

Method Overriding:

Method overriding occurs when a subclass provides a specific implementation of a method that is already defined in its superclass. The method in the subclass has the same signature (name and parameters) as the one in the superclass, thereby replacing or overriding the behavior of the superclass method.

For example:

class Animal {

    void sound() {

        System.out.println("Animal makes a sound");

    }

}

class Dog extends Animal {

    void sound() {

        System.out.println("Dog barks");

    }

}

public class Main {

    public static void main(String[] args) {

        Dog dog = new Dog();

        dog.sound(); // This will print "Dog barks" instead of "Animal makes a sound"

    }

}

In this example, the `Dog` class overrides the `sound()` method defined in the `Animal` class, providing its own implementation.

Method Overriding in Multilevel Inheritance:

Method overriding can also occur in multilevel inheritance, where a subclass overrides a method that it inherits from its superclass, and subsequent subclasses in the hierarchy can further override the method.

class Animal {

    void sound() {

        System.out.println("Animal makes a sound");

    }

}

class Dog extends Animal {

    void sound() {

        System.out.println("Dog barks");

    }

}

class Labrador extends Dog {

    void sound() {

        System.out.println("Labrador growls");

    }

}

public class Main {

    public static void main(String[] args) {

        Labrador labrador = new Labrador();

        labrador.sound(); // This will print "Labrador growls" because Labrador overrides the sound() method

    }

}

In this example, the `Labrador` class overrides the `sound()` method inherited from the `Dog` class, which itself overrides the `sound()` method from the `Animal` class.