Abstraction in Java

Abstraction in Java is a process of hiding the implementation details and showing only the functionality to the user. It helps to reduce complexity and increase efficiency.
Key Points:
Abstraction = Hiding Internal Details
Only show what an object does, not how it does it.

Achieved using:
1.Abstract Classes
2.Interfaces

1. Abstract Class:
Can have abstract methods (no body) and concrete methods (with body).
Cannot be instantiated.
Used when classes share common behavior.
Example. 
abstract class Animal {
    abstract void sound(); // abstract method

    void sleep() {
        System.out.println("Sleeping...");
    }
}

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

2. Interface:
All methods are abstract (by default in older versions of Java).

A class implements an interface to provide behavior.


interface Vehicle {
    void start();
}

class Car implements Vehicle {
    public void start() {
        System.out.println("Car starts");
    }
}

Real-Life Example:
TV Remote (Abstraction):
You press the power button, it turns on.
You don’t know the internal wiring.

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