private function __construct(){ } static function getObj(){ if(is_null(self::$obj)){ self::$obj = new $e(); } return self::$obj; } } $d = e::getObj(); $d->uname = 100; echo $d->uname; echo '<br />'; $e = e::getObj(); echo $e->uname; echo '<br />'; $e->uname=200; echo $e->uname; echo '<br />'; echo $d->uname; /* class e{ //服务于对象的 function __construct(){ } //服务于类的 static function __construct(){