$hander = new A();

 session_set_save_handler(
                array(&$hander,"open"),
                array(&$hander,"close"),
                array(&$hander,"read"),
                array(&$hander,"write"),
                array(&$hander,"destroy"),
                array(&$hander,"gc"));
        }

看手册中 session_set_save_handler中这一段并没有加&

 session_set_save_handler(
                array($hander,"open"),
                array($hander,"close"),
                array($hander,"read"),
                array($hander,"write"),
                array($hander,"destroy"),
                array($hander,"gc"));
        }

这个地方，实例化后，我就是不明白，都是调用同一个对象中的方法，加&与不加&有什么区别，

当然$b =& $a;这样的我是懂的