PHP Object-Oriented Programming (OOP)

<?php

class GroceryStore {
    private $products = [
        1 => ['name' => 'Organic Apples', 'price' => 2.99, 'stock' => 50],
        2 => ['name' => 'Whole Milk 1L', 'price' => 1.49, 'stock' => 30],
        3 => ['name' => 'Whole Wheat Bread', 'price' => 2.29, 'stock' => 20]
    ];

    public function getProducts() {
        return $this->products;
    }

    public function addToCart($productId, $quantity) {
        if (isset($this->products[$productId])) {
            $item = $this->products[$productId];
            $total = $item['price'] * $quantity;
            return "Added {$quantity}x {$item['name']} to cart. Total: \${$total}";
        }
        return "Product not found.";
    }
}

$store = new GroceryStore();
echo $store->addToCart(1, 3) . "\n";
?>

Added 3x Organic Apples to cart. Total: $8.97

<?php

class Car {
    public $brand;
    public $model;

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

    public function getDetails() {
        return "Car: {$this->brand} {$this->model}";
    }
}

$myCar = new Car("Toyota", "Corolla");
echo $myCar->getDetails() . "\n";
?>

Car: Toyota Corolla

<?php

class Animal {
    protected $name;

    public function __construct($name) {
        $this->name = $name;
    }
}

class Dog extends Animal {
    public function bark() {
        return "{$this->name} says: Woof Woof!";
    }
}

$dog = new Dog("Buddy");
echo $dog->bark() . "\n";
?>

Buddy says: Woof Woof!

<?php

namespace App\Controllers;

class Home {
    public function index() {
        $data = ['title' => 'Welcome to CodeIgniter 4'];
        return "Controller Response: " . $data['title'];
    }
}

$controller = new Home();
echo $controller->index() . "\n";
?>

Controller Response: Welcome to CodeIgniter 4