PHP中的值对象

Question

如何创建不允许动态属性的PHP类？

class User
{
  public $username;
  public $password;
}

$user = new User;
$user->username = "bill.gates";

// This is a dynamic property and I need setting it to be considered illegal.
$user->something = 123;

Answer 1

拯救的神奇方法:

class User
{
  public $username;
  public $password;

  public function __set($key, $value) {
    throw new Exception('illegal'); // or just trigger_error()
  }
}