Question

我有以下代码生成JSON变量。我使用内置json_decode函数的php来解码json变量，但是我在解码JSOn变量后得到NULL。

$a=array("targetAction"=>"getHeadFields","targetHead"=>$table_name);
$obj1 =  Post_Uamsdata($a);
echo $obj1;

$file = json_decode($obj1,true);
var_dump($file);

$ obj1是我的json变量。每当我回应它，我得到如下结果：

{"success":"yes","error":"","message":"","arguments":"[{\"fieldNo\":\"1\",\"fieldName\":\"ItemType\",\"fieldType\":\"character(16)\",\"notnull\":\"f\",\"fieldLabel\":null,\"primary_key\":\"f\",\"default\":null,\"fieldOption\":[]},{\"fieldNo\":\"2\",\"fieldName\":\"Long\",\"fieldType\":\"character(20)\",\"notnull\":\"f\",\"fieldLabel\":null,\"primary_key\":\"f\",\"default\":null,\"fieldOption\":[]},{\"fieldNo\":\"3\",\"fieldName\":\"Lat\",\"fieldType\":\"character(20)\",\"notnull\":\"f\",\"fieldLabel\":null,\"primary_key\":\"f\",\"default\":null,\"fieldOption\":[]},{\"fieldNo\":\"4\",\"fieldName\":\"MapDate\",\"fieldType\":\"character(16)\",\"notnull\":\"f\",\"fieldLabel\":null,\"primary_key\":\"f\",\"default\":null,\"fieldOption\":[]},{\"fieldNo\":\"5\",\"fieldName\":\"FieldNote\",\"fieldType\":\"character(64)\",\"notnull\":\"f\",\"fieldLabel\":null,\"primary_key\":\"f\",\"default\":null,\"fieldOption\":[]}]"}

我已经在在线json验证器中检查了它，并且它说这个JSOn是有效的。但每当我将这个$ obj1解码为$ file时，我总是得到NULL。

Answer 1

json_decode将接受json格式的字符串并返回混合类型。请仔细阅读这个有用的链接

http://php.net/manual/en/function.json-decode.php

-Vamsi

Answer 2

在json_decode后我们得到以下内容，但我想这不是你想要的。您还希望解析fieldNo，fieldName等。

  $json = '{"success":"yes","error":"","message":"","arguments":"[{\"fieldNo\":\"1\",\"fieldName\":\"ItemType\",\"fieldType\":\"character(16)\",\"notnull\":\"f\",\"fieldLabel\":null,\"primary_key\":\"f\",\"default\":null,\"fieldOption\":[]},{\"fieldNo\":\"2\",\"fieldName\":\"Long\",\"fieldType\":\"character(20)\",\"notnull\":\"f\",\"fieldLabel\":null,\"primary_key\":\"f\",\"default\":null,\"fieldOption\":[]},{\"fieldNo\":\"3\",\"fieldName\":\"Lat\",\"fieldType\":\"character(20)\",\"notnull\":\"f\",\"fieldLabel\":null,\"primary_key\":\"f\",\"default\":null,\"fieldOption\":[]},{\"fieldNo\":\"4\",\"fieldName\":\"MapDate\",\"fieldType\":\"character(16)\",\"notnull\":\"f\",\"fieldLabel\":null,\"primary_key\":\"f\",\"default\":null,\"fieldOption\":[]},{\"fieldNo\":\"5\",\"fieldName\":\"FieldNote\",\"fieldType\":\"character(64)\",\"notnull\":\"f\",\"fieldLabel\":null,\"primary_key\":\"f\",\"default\":null,\"fieldOption\":[]}]"}';

 $arr = json_decode($json, true);
 echo "<pre>";
 print_r($arr);

输出如下

 Array
 (
   [success] => yes
   [error] => 
   [message] => 
   [arguments] =>  [{"fieldNo":"1","fieldName":"ItemType","fieldType":"character(16)","notnull":"f","fieldLabel":null,"primary_key":"f","default":null,"fieldOption":[]},{"fieldNo":"2","fieldName":"Long","fieldType":"character(20)","notnull":"f","fieldLabel":null,"primary_key":"f","default":null,"fieldOption":[]},{"fieldNo":"3","fieldName":"Lat","fieldType":"character(20)","notnull":"f","fieldLabel":null,"primary_key":"f","default":null,"fieldOption":[]},{"fieldNo":"4","fieldName":"MapDate","fieldType":"character(16)","notnull":"f","fieldLabel":null,"primary_key":"f","default":null,"fieldOption":[]},{"fieldNo":"5","fieldName":"FieldNote","fieldType":"character(64)","notnull":"f","fieldLabel":null,"primary_key":"f","default":null,"fieldOption":[]}]
  )

Answer 3

由于http://php.net/manual/en/function.json-decode.php表示该函数仅适用于UTF-8编码的字符串，请尝试以下操作：

$file = json_decode(mb_convert_encoding($obj1, 'UTF-8'),true);

无法解码json变量

3 个答案: