Inheritance in JAVA

❔ What is Inheritance?

Inheritance allows a class (child/subclass) to inherit properties and behaviors (variables and methods) from another class (parent/superclass).

Reusability: Write once, use multiple times.

🚀 Why Use Inheritance?

• Reuse code from existing classes

• Avoid duplication

• Support hierarchical classifications

• Enables polymorphism and method overriding

🔸 Syntax:

class Parent {
    // parent class
}

class Child extends Parent {
    // child class inherits Parent
}

👨‍👩‍👧‍👦 Real-Life Analogy

Vehicle is a general class. Car and Bike are specific types of vehicles.

Example: Single Inheritance

class Animal {
    void eat() {
        System.out.println("This animal eats food.");
    }
}

class Dog extends Animal {
    void bark() {
        System.out.println("The dog barks.");
    }
}

public class Main {
    public static void main(String[] args) {
        Dog d = new Dog();
        d.eat();   // inherited
        d.bark();  // own method
    }
}

This animal eats food.
The dog barks.

👪 Types of Inheritance in Java

❌ Java does not support multiple inheritance (a class inheriting from more than one class) using classes. It supports it via interfaces.

👨‍👧‍👦 Multilevel Inheritance Example

class Animal {
    void eat() {
        System.out.println("Eats food");
    }
}

class Dog extends Animal {
    void bark() {
        System.out.println("Barks");
    }
}

class Puppy extends Dog {
    void weep() {
        System.out.println("Weeps");
    }
}

public class Main {
    public static void main(String[] args) {
        Puppy p = new Puppy();
        p.eat();  // from Animal
        p.bark(); // from Dog
        p.weep(); // from Puppy
    }
}

Eats food
Barks
Weeps

📝 Important Notes

• Use extends keyword to inherit

• Child class can access all non-private members of the parent

• Constructors are not inherited

• Method overriding is common in inheritance