這是PHP后端代碼 ?json_encode($return)；這是打印出來的數(shù)據(jù) {"error":0,"area_list":[{"area_id":"2","area_pid":"1","area_name":"\u5317\u4eac","area_sort":"0","first_pinyin":"b","is_open":"1","area_url":"bj","area_ip_desc":"\u5317\u4eac\u5e02","area_type":"2","is_hot":"1"}]}； 但是在前端為什么area_name 后面的\u5317\u4eac，能直接解析成中文呢？是個什么原理呢？