PHP Manual Function Reference Other Basic Extensions SPL Miscellaneous Classes and Interfaces SplObserver ArrayObject::unserialize SplObserver::update The SplObserver interface (PHP 5 >= 5.1.0) Introduction The SplObserver interface is used alongside SplSubject to implement the Observer Design Pattern. Interface synopsis SplObserver { /* Methods */ abstract public void update ( SplSubject $subject ) } Table of ContentsSplObserver::update — Receive update from subject