<?php$mysqli=new mysqli('localhost','root','root','imooc');var_dump($mysqli);打印結(jié)果：object(mysqli)[1] ?public 'affected_rows' => null ?public 'client_info' => null ?public 'connect_errno' => null ?public 'connect_error' => null?............................. ? ? ? ? ? ? =>null?............................. ? ? ? ? ? ? =>null ?public 'thread_id' => null ?public 'warning_count' => null返回的結(jié)果為什么全部是NULL?使用print_r()就正常.謝謝!