package Java_OOP;

// Abstraction in Java

/**

* Abstraction is the process of hiding complex implementation details

* and showing only the essential features to the user.

*

* In Java, abstraction can be achieved in two ways:

*

* 1. Abstract Classes (0–100% abstraction)

* - Declared with the 'abstract' keyword.

* - Can have both abstract methods (no body) and concrete methods.

* - Cannot be instantiated directly.

*

* 2. Interfaces (100% abstraction)

* - Declared with the 'interface' keyword.

* - All methods are abstract by default (until Java 8, which added default/static methods).

* - A class implements an interface to provide its behavior.

*/

public class AbstractionExample {

public static void main(String[] args) {

// --- Abstract Class Example ---

System.out.println("Abstract Class Example:");

Animal myDog = new Dog();

Animal myCat = new Cat();

myDog.makeSound();

myDog.eat();

myCat.makeSound();

// --- Interface Example ---

System.out.println("\nInterface Example:");

Vehicle car = new Car();

Vehicle bike = new Motorcycle();

car.start();

bike.start();

car.stop();

bike.stop();

}

}

// Example 1: Abstract Class

abstract class Animal {

// Abstract method (no body) — must be implemented by subclasses

abstract void makeSound();

// Concrete method — can be used by all subclasses

void eat() {

System.out.println("This animal is eating...");

}

}

// Subclasses provide specific implementations

class Dog extends Animal {

@Override

void makeSound() {

System.out.println("The dog barks!");

}

}

class Cat extends Animal {

@Override

void makeSound() {

System.out.println("The cat meows!");

}

}

// Example 2: Interface

interface Vehicle {

void start();

void stop();

}

class Car implements Vehicle {

public void start() {

System.out.println("Car is starting...");

}

public void stop() {

System.out.println("Car is stopping...");

}

}

class Motorcycle implements Vehicle {

public void start() {

System.out.println("Motorcycle is starting...");

}

public void stop() {

System.out.println("Motorcycle is stopping...");

}

}