Netbeans动态类型提示/铸造

Question

In NetBeans we can do type casting as below -

/**
 *
 * @var My_Db_Table_Abstract
 */
protected $_db;

But in my case the variable $_db may be instance of different classes, because it's value is assigned dynamically like below.

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

Is it possible to make the type (here My_Db_Table_Abstract) dynamic?

Answer 1

You should use PHP's type-hinting feature in your constructor's parameters to guarantee that what's passed in is an object of the type you require.

public function __construct (My_Db_Table_Abstract $db) {
    $this->_db = $db;
}

This will prevent you from passing anything except My_Db_Table_Abstract or a subclass of My_Db_Table_Abstract into your constructor.