json_encode转义中文问题

默认情况下php的 json_decode 方法会把特殊字符进行转义，还会把中文转为Unicode编码形式。

这使得数据库查看文本变得很麻烦。所以我们需要限制对于中文的转义。

对于PHP5.4+版本，json_decode函数第二个参数，可以用来限制转义范围。

要限制中文，使用JSON_UNESCAPED_UNICODE参数。

      json_encode($a, JSON_UNESCAPED_UNICODE); 

例如：在保存数组中中文对应的分数时，其中包含有中文，在将数组转换成字符串json_encode()时，加入参数 

JSON_UNESCAPED_UNICODE，就可以防止中文数据被转义。

        $answer_score[0] = array("中文1" => mt_rand(95,99));//中文名称对应的分数
        $answer_score[1] = array("中文2" => mt_rand(81,87));
        $answer_score[2] = array("中文3" => mt_rand(70,80));
        $answer_score[3] = array("中文4" => mt_rand(70,80));
        $answer_score[4] = array("中文5" => mt_rand(70,80));
        $json_answer_score = (json_encode($answer_score , JSON_UNESCAPED_UNICODE));
        $model = new SweepstakesModel();
        $selfAnswer = $model->updateGroupxzSelfanswer("pengjun123" , "werwef" , $json_answer_score , "军军");

 在数据库中存储的结果如下：

Array
(
    [id] => 1
    [openid] => pengjun123
    [nickname] => 彭军
    [icon] => http://wx.qlogo.cn/mmopen/qhDbvnE5DMn5stSjg52mmB4Tj1nMVCticRShFfBriaE8lAsF3cgzNtZGogVJXUyUOG1W6hQKFWBM8SZhEnIrTyb8LO1nc6sgQd/0
    [answer] => werwef
    [addtime] => 2017-08-15 18:24:22
    [subtime] => 2017-08-28 12:13:58
    [answer_score] => [{"中文1":95},{"中文2":82},{"中文3":72},{"中文4":76},{"中文5":70}]
    [answer_point] => 军军
    [extend] => 1
    [help_answer_score] => 
    [helppositionName] => 
)

如果不使用 JSON_UNESCAPED_UNICODE ， 则会出现如下的转义效果

Array
(
    [id] => 1
    [openid] => pengjun123
    [nickname] => 彭军
    [icon] => http://wx.qlogo.cn/mmopen/qhDbvnE5DMn5stSjg52mmB4Tj1nMVCticRShFfBriaE8lAsF3cgzNtZGogVJXUyUOG1W6hQKFWBM8SZhEnIrTyb8LO1nc6sgQd/0
    [answer] => werwef
    [addtime] => 2017-08-15 18:24:22
    [subtime] => 2017-08-28 12:21:19
    [answer_score] => [{"u4e2du65871":98},{"u4e2du65872":87},{"u4e2du65873":77},{"u4e2du65874":79},{"u4e2du65875":78}]
    [answer_point] => 军军
    [extend] => 1
    [help_answer_score] => 
    [helppositionName] => 
)

这种转义之后的数据在数据库很难阅读