---
title: "Inheritance"
description: Inheritance types, the super keyword, method overriding, and access modifiers in inheritance.
---
## Definition

Inheritance allows a class (subclass) to acquire the properties and methods of another class (superclass). It promotes code reuse and establishes an "is-a" relationship.

```java
class Subclass extends Superclass {
    // additional fields and methods
}
```

## Types of Inheritance

- **Single** — One subclass extends one superclass.
- **Multilevel** — A subclass extends another subclass (chain).
- **Hierarchical** — Multiple subclasses extend the same superclass.

> Java does not support multiple inheritance of classes. Use interfaces instead.

## The `super` Keyword

- `super.method()` — Calls the superclass version of an overridden method.
- `super(args)` — Calls the superclass constructor from a subclass constructor.

## Method Overriding

A subclass provides its own implementation of a method already defined in the superclass. The method signature must match exactly.

## Access Modifiers in Inheritance

- `public` and `protected` members are inherited.
- `private` members are not directly accessible in subclasses.
- Default (package-private) members are inherited only within the same package.

## Example

```java
// InheritanceDemo.java
// Demonstrates inheritance and method overriding in Java.

// Superclass
class Animal {
	// Method in superclass
	void eat() {
		System.out.println("Animal eats");
	}
}

// Subclass extends superclass
class Dog extends Animal {
	// Overriding method
	void eat() {
		System.out.println("Dog eats bones");
	}
}

public class InheritanceDemo {
	public static void main(String[] args) {
		// Create Dog object and call eat()
		Dog d = new Dog();
		d.eat();
	}
}
```

> Full source: [`examples/09-inheritance/InheritanceDemo.java`](https://github.com/University-Of-Sri-Jayewardenepura/Java/blob/main/examples/09-inheritance/InheritanceDemo.java)