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.