Classes and Objects in PHP

PHP

"PHP is a server-side programming language that is flexible, easy to learn, and still the backbone of many websites, even though it is often thought to be outdated"

Welcome to the exciting world of Object-Oriented Programming (OOP) in PHP!  One of the key concepts in OOP is classes and objects, which allow you to create structured, reusable, and efficient code. In this guide, we’ll break down classes and objects with fun explanations and real-world examples. Let’s get started! 

What are Classes and Objects?

A class is like a blueprint for creating objects. An object is an instance of a class that has properties (variables) and methods (functions).

Imagine a Car class:

• Properties: brand, color, speed
• Methods: start(), accelerate(), brake()

Creating a Class and Object in PHP

Example: Defining a Car Class

class Car {
    public $brand;
    public $color;
    
    public function __construct($brand, $color) {
        $this->brand = $brand;
        $this->color = $color;
    }
    
    public function drive() {
        return "The $this->color $this->brand is driving!";
    }
}

$myCar = new Car("Toyota", "red");
echo $myCar->drive();
// Output: The red Toyota is driving!

Real-World Example: Online Shopping Cart

Let’s build a simple ShoppingCart class to handle items:

class ShoppingCart {
    private $items = [];
    
    public function addItem($item) {
        $this->items[] = $item;
    }
    
    public function getItems() {
        return $this->items;
    }
}

$cart = new ShoppingCart();
$cart->addItem("Laptop");
$cart->addItem("Mouse");
print_r($cart->getItems());
// Output: Array ( [0] => Laptop [1] => Mouse )

Object Methods and Properties

Modifying and Accessing Properties

class Person {
    public $name;
    public $age;
    
    public function setName($name) {
        $this->name = $name;
    }
    
    public function getName() {
        return $this->name;
    }
}

$person = new Person();
$person->setName("John Doe");
echo $person->getName();
// Output: John Doe

The Power of Constructors and Destructors

Constructor Example

class User {
    public $username;
    
    public function __construct($username) {
        $this->username = $username;
    }
    
    public function welcome() {
        return "Welcome, $this->username!";
    }
}

$user = new User("Alice");
echo $user->welcome();
// Output: Welcome, Alice!

Destructor Example

class Logger {
    public function __destruct() {
        echo "Logging out...";
    }
}

$log = new Logger();
// When script ends, "Logging out..." will be printed automatically.

Now you understand Classes and Objects in PHP with practical examples! Creating and using classes and objects, Defining properties and methods, Using constructors and destructors.