🌳 Inheritance in Java – Reusing Code Like a Pro!

In Object-Oriented Programming (OOP), Inheritance is like a family tree 👨‍👩‍👧‍👦 — where child classes inherit qualities from their parent class.

🌟 What is Inheritance?

👉 Inheritance is the mechanism in Java where one class (child/subclass) acquires the properties and behaviors (fields & methods) of another class (parent/superclass).

It helps in code reusability and establishes a natural hierarchy between classes.

🏡 Real-World Analogy

Think about a Car 🚗:

• A general Car (parent class) has properties like speed, fuel, wheels.

• A SportsCar (child class) inherits all of these, but can also add its own features like turbo boost.

So, the child doesn’t need to redefine everything — it just reuses and adds more!

Terms used in Inheritance:

• Class: A class is a group of objects which have common properties. It is a template or blueprint from which objects are created.
• Sub Class/Child Class: Subclass is a class which inherits the other class. It is also called a derived class, extended class, or child class.
• Super Class/Parent Class: Superclass is the class from where a subclass inherits the features. It is also called a base class or a parent class.
• Reusability: As the name specifies, reusability is a mechanism which facilitates you to reuse the fields and methods of the existing class when you create a new class. You can use the same fields and methods already defined in the previous class.

⚡ Types of Inheritance in Java

🔹 Single Inheritance → One class inherits from another.
🔹 Multilevel Inheritance → A class inherits from a class which inherits from another.
🔹 Hierarchical Inheritance → Multiple classes inherit from one parent.

❌ Multiple Inheritance (two classes as parents) is not supported directly in Java (to avoid ambiguity), but achieved via interfaces.

🖥️ Java Example: Inheritance in Action

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

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

// Main class
public class Main {
    public static void main(String[] args) {
        Dog d = new Dog();
        d.eat();   // Inherited from Animal
        d.bark();  // Defined in Dog
    }
}

✅ Output:

This animal eats food.  
The dog barks.  

🎯 Benefits of Inheritance

• 🔄 Code Reusability → Write once, reuse everywhere.

• 🏗 Extensibility → Add new features without touching existing code.

• 🧩 Organization → Creates a clear class hierarchy.

• 🚀 Faster Development → Less code duplication = faster coding.

✨ Quick Summary

👉 Inheritance = Parent → Child relationship in OOP.
The child class inherits methods & variables from the parent, making code cleaner, shorter, and more powerful.

💡 Pro Tip: Always use inheritance when there is an “is-a” relationship.
Example: Dog is an Animal ✅ | Car is a Vehicle ✅ | Keyboard is a Computer ❌ (wrong, that’s composition).