note 76643 added to language.oop5.magic

Another small thing that is important to note about __sleep() and privte member variables: <?php class A { private $a; public function __construct() { $this->a = 1; } } class B extends A { protected $b; public function __construct() { parent::__construct(); $this->b = 2; } function __sleep() { return array('a', 'b'); } } serialize(new B); ?> result: Notice: serialize(): "a" returned as member variable from __sleep() but does not exist in ... To summerize: in a given class hierarchy in which parent classes contain private member variables, those variables are serialized when __sleep() is not defined. However, once __sleep() is defined, there is no way to make those private member variables serialized as well. From that point on, serialization is performed from the visibility scope of the subclass. It is particularly important to note this little quirk when designing base classes that their derivables may be serialized, or when subclassing an external library class. ---- Server IP: 69.147.83.197 Probable Submitter: 64.236.80.62 ---- Manual Page -- http://www.php.net/manual/en/language.oop5.magic.php Edit -- https://master.php.net/note/edit/76643 Del: integrated -- https://master.php.net/note/delete/76643/integrated Del: useless -- https://master.php.net/note/delete/76643/useless Del: bad code -- https://master.php.net/note/delete/76643/bad+code Del: spam -- https://master.php.net/note/delete/76643/spam Del: non-english -- https://master.php.net/note/delete/76643/non-english Del: in docs -- https://master.php.net/note/delete/76643/in+docs Del: other reasons-- https://master.php.net/note/delete/76643 Reject -- https://master.php.net/note/reject/76643 Search -- https://master.php.net/manage/user-notes.php