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

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

class Order{
 public $user;
 public $productName;
 public $productPrice;
 public function __construct(\Product $product \User $user){
    $this->productName  = $product->name;
    $this->productPrice = $product->name;
    $this->user         = $user->name;

    return $this;
 }

 $user    = new User("Hungry");
 $product = new Product(100,"banana");
 $order   = new Order($product, $user);
}