解码使用Javascript从PHP检索到的json对象

Question

I am having trouble using the json object echoed from php to javascript. In the php file I define

$json = '{"a":1,"b":2,"c":3,"d":4,"e":5}';
echo($json);

and then in javascript file I want to access this object.

$("#test_btn").click(function() {
                $.get("serverside.php", function(data, status) { 
                   console.log("data " , data["a"]); //undefined
                   console.log(JSON.parse(data)); // error
                });
            });

I get undefined for data["a"] and an error for JSON.parse. How should I use the returend data?

Answer 1

Based on your comment (echoing several json strings), you should do the following:

1. Initialize an empty results array;
2. Read your file and put it in an array or object using json_decode() ;
3. Add this array / object to your results array;
4. At the end, use json_encode() to encode and echo out your results array.

Answer 2

在尝试访问data['a']之前，必须先创建一个JSON.parse(data)然后从PHP发送一个标头，该标头隐含地告诉浏览器数据输出将是JSON。

header ('Content-Type: application/json');

Answer 3

The problem might be that PHP is returning a string that looks like JSON.

In JS it might help to JSON.parse(data) to convert from string to JSON object, then you can access it.

$("#test_btn").click(function() {
  $.get("serverside.php", function(data, status) {
    $json = JSON.parse(data);
    console.log("data " , $json["a"]); // should now return 1
  });
});

Answer 4

您需要将json_encode或在javascript中解析