SplObserver
PHP Manual

SplObserver::update

(PHP 5 >= 5.1.0, PHP 7)

SplObserver::update — Receive update from subject

Description

abstract public void SplObserver::update ( SplSubject $subject )

This method is called when any SplSubject to which the observer is attached calls SplSubject::notify().

Warning

This function is currently not documented; only its argument list is available.

Parameters

subject

The SplSubject notifying the observer of an update.

Return Values

No value is returned.

SplObserver
PHP Manual