SplSubject::attach (PHP 5 >= 5.1.0, PHP 7)SplSubject::attach — Attach an SplObserver 说明 abstract public SplSubject::attach ( SplObserver $observer ) : void Attaches an SplObserver so that it can be notified of updates. Warning本函数还未编写文档,仅有参数列表。 参数 observer The SplObserver to attach. 返回值 没有返回值。