lognum=rand(1,10);        $this->hobby=$hobby;        $this->observers=new SplObjectStorage();    }    public function login()    {        $this->notify();//操作session    }    public function attach(SPLObserver $observer)    {        $this->observers->attach($observer);    }    public function detach(SPLObserver $observer)    {        $this->observers->detach($observer);    }    public function notify()    {        $this->observers->rewind();        while ($this->observers->valid()) {            $observer=$this->observers->current();            $observer->update($this);            $this->observers->next();        }    }}class secrity implements SPLObserver{    public function update(SplSubject $subject)    {        if($subject->lognum<3)        {            echo "这是第".$subject->lognum."次安全登录";        }else        {            echo "这是第".$subject->lognum."次登录,危险";        }    }}class ad implements SPLObserver{    public function update(SplSubject $subject)    {        if($subject->hobby=="sports")        {            echo "台球赛门票预定";        }else        {            echo "还是好好学习吧";        }    }}$user=new user("study");$user->attach(new secrity());$user->attach(new ad());$user->login();?>