Object-Oriented Programming (OOP) in PHP

In OOP, a class is a blueprint that defines the structure and behavior of objects. Objects are instances of classes, representing real-world entities or abstract concepts. Let’s create a simple Car class with a couple of properties and methods:

<?php
class Car {
public $make;
public $model;

public function startEngine() {
return “Engine started!”;
}

public function stopEngine() {
return “Engine stopped!”;
}
}

// Create an object of the Car class
$myCar = new Car();
$myCar->make = “Toyota”;
$myCar->model = “Camry”;
?>

Properties are the attributes or data members of a class, while methods are the functions that define the behavior of objects. In the example above, $make and $model are properties, while startEngine() and stopEngine() are methods.

Constructors and destructors are special methods in a class. The constructor (__construct()) is called automatically when an object is created, allowing you to initialize properties or perform setup tasks. The destructor (__destruct()) is called when the object is destroyed, typically used for cleanup tasks. Let’s add a constructor to the Car class:

<?php
class Car {
public $make;
public $model;

public function __construct($make, $model) {
$this->make = $make;
$this->model = $model;
}

// Rest of the methods…
}

// Create an object of the Car class with constructor arguments
$myCar = new Car(“Toyota”, “Camry”);
?>

Inheritance allows a class (child class) to inherit properties and methods from another class (parent class). This promotes code reuse and hierarchy. Polymorphism allows objects of different classes to be treated as objects of a common parent class. Let’s demonstrate inheritance and polymorphism with an example:

<?php
class Vehicle {
public function startEngine() {
return “Engine started!”;
}
}

class Car extends Vehicle {
// Car class inherits startEngine() method from Vehicle class
}

class Bicycle extends Vehicle {
// Bicycle class also inherits startEngine() method from Vehicle class
}

// Polymorphism example
function startVehicleEngine(Vehicle $vehicle) {
return $vehicle->startEngine();
}

$myCar = new Car();
$myBicycle = new Bicycle();

echo startVehicleEngine($myCar); // Output: Engine started!
echo startVehicleEngine($myBicycle); // Output: Engine started!
?>

Namespaces are used to avoid naming conflicts and organize classes and functions into logical groups. They provide a way to encapsulate code and improve code readability. Let’s create a namespace for our Car class:

<?php
namespace MyNamespace;

class Car {
// Class code…
}

$myCar = new MyNamespace\Car();
?>