[WeakMap :: \_\_ construct](https://www.php.net/manual/en/weakmap.construct.php)—构造一个新地图 [WeakMap :: count](https://www.php.net/manual/en/weakmap.count.php)—计算地图中实时条目的数量 [WeakMap :: current](https://www.php.net/manual/en/weakmap.current.php)—返回迭代时的当前值 [WeakMap :: key](https://www.php.net/manual/en/weakmap.key.php)—返回正在迭代的当前密钥 [WeakMap :: next](https://www.php.net/manual/en/weakmap.next.php)—前进到下一个地图元素 [WeakMap :: offsetExists](https://www.php.net/manual/en/weakmap.offsetexists.php)—检查地图中是否存在某个对象 [WeakMap :: offsetGet](https://www.php.net/manual/en/weakmap.offsetget.php)—返回由某个对象指向的值 [WeakMap :: offsetSet](https://www.php.net/manual/en/weakmap.offsetset.php)—用新的键值对更新地图 [WeakMap :: offsetUnset](https://www.php.net/manual/en/weakmap.offsetunset.php)—从地图上删除一个条目 [WeakMap :: rewind](https://www.php.net/manual/en/weakmap.rewind.php)—将迭代器[后退](https://www.php.net/manual/en/weakmap.rewind.php)到地图的开头 [WeakMap :: valid](https://www.php.net/manual/en/weakmap.valid.php)—返回迭代器是否仍在有效的地图元素上