PHP オブジェクト指向プログラミングの深い理解: クラスとオブジェクト間の対話

class Person {
  private $name;
  private $age;

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

  public function getName() {
    return $this->name;
  }

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

  public function getAge() {
    return $this->age;
  }

  public function setAge($age) {
    $this->age = $age;
  }
}

$person = new Person('John Doe', 30);

echo $person->getName(); // 输出："John Doe"

$person->setAge(35);

class Product {
  private $name;
  private $price;

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

  // ...
}

class Cart {
  private $products = [];

  public function addProduct(Product $product) {
    $this->products[] = $product;
  }

  public function getTotalPrice() {
    $totalPrice = 0;
    foreach ($this->products as $product) {
      $totalPrice += $product->getPrice();
    }

    return $totalPrice;
  }

  // ...
}

$cart = new Cart();
$product1 = new Product('Apple', 10);
$product2 = new Product('Orange', 5);

$cart->addProduct($product1);
$cart->addProduct($product2);

echo $cart->getTotalPrice(); // 输出："15"