send = $send; } abstract public function msg($content); public function send($to,$content){ $content = $this->msg($content); $this->send->send($to,$content); }}interface Send { public function send($to,$content);}class zn implements Send { public function send($to,$content){ echo '站内给' . $to .',内容是:' . $content; }}class email implements Send { public function send($to,$content){ echo 'email给' . $to .',内容是:' . $content; }}class sms implements Send { public function send($to,$content){ echo '短信给' . $to .',内容是:' . $content; }}class commoninfo extends info { public function msg($content){ return '普通' . $content; }}class warninfo extends info { public function msg($content){ return '紧急' . $content; }}class dangerinfo extends info { public function msg($content){ return '特急' . $content; }}//站内发普通信息$commoninfo = new commoninfo(new zn());$commoninfo->send('小明','吃饭了');echo '';//用手机发特急信息$dangerinfo = new dangerinfo(new sms());$dangerinfo->send('小刚','你家失火了');