以下是一个简单的PHP对象模型实例，我们将创建一个购物车系统，其中包含商品类、购物车类和订单类。
商品类（Product.php）
```php
class Product {
public $id;
public $name;
public $price;
public function __construct($id, $name, $price) {
$this->id = $id;
$this->name = $name;
$this->price = $price;
}
public function getTotalPrice() {
return $this->price;
}
}
>
```
购物车类（Cart.php）
```php
class Cart {
private $products = [];
public function addProduct(Product $product) {
$this->products[$product->id] = $product;
}
public function removeProduct($id) {
unset($this->products[$id]);
}
public function getTotalPrice() {
$total = 0;
foreach ($this->products as $product) {
$total += $product->getTotalPrice();
}
return $total;
}
public function getProducts() {
return $this->products;
}
}
>
```
订单类（Order.php）
```php
class Order {
private $cart;
private $date;
public function __construct(Cart $cart) {
$this->cart = $cart;
$this->date = date('Y-m-d H:i:s');
}
public function getTotalPrice() {
return $this->cart->getTotalPrice();
}
public function getProducts() {
return $this->cart->getProducts();
}
public function getDate() {
return $this->date;
}
}
>
```
使用示例
```php
include 'Product.php';
include 'Cart.php';
include 'Order.php';
// 创建商品实例
$product1 = new Product(1, 'Laptop', 1000);
$product2 = new Product(2, 'Smartphone', 500);
// 创建购物车实例
$cart = new Cart();
$cart->addProduct($product1);
$cart->addProduct($product2);
// 创建订单实例
$order = new Order($cart);
// 输出订单信息
echo "
