Object Composition and Abstractions in OOP

Object composition and abstraction are fundamental concepts in PHP object-oriented programming (OOP).

Object Composition:

Object composition is a technique where an object is made up of one or more other objects. This allows for:

• Code reuse


• Easier maintenance


• More flexibility

In PHP, object composition is achieved by including one class within another using a property or method.

Abstraction:

Abstraction is the concept of showing only the necessary information to the outside world while hiding the internal details. In PHP, abstraction is achieved using:

• Abstract classes


• Interfaces


• Encapsulation (access modifiers)

Abstraction helps to:

• Reduce complexity


• Improve code organization


• Increase flexibility

An example of object composition and abstraction in PHP is:

<?php 



// Abstraction

abstract class Vehicle {

  abstract public function move();

}



// Object Composition

class Car {

  private $engine;



  public function __construct(Engine $engine) {

    $this->engine = $engine;

  }



  public function move() {

    $this->engine->start();

    echo "Car is moving";

  }

}



class Engine {

  public function start() {

    echo "Engine started";

  }

}



$car = new Car(new Engine());

$car->move();

In this example, the Car class is composed of an Engine object, demonstrating object composition. The Vehicle abstract class provides abstraction, hiding the internal details of the move method from outside.

I hope that you have clearly understood it.