New to JSON, what can I do with this json response

Hi,

A website returns the following JSON response, how would I consume it (in javascript)?

[{"ID1":9996,"ID2":22}]

Is JSON simply returning an array?

From stackoverflow

• We use:

  function evalResponse(response) {
      var xyz123 = null;
      eval("xyz123 = " + response);
      return xyz123;
  }
  

  An alternative method is to simply use:

  var myObj = eval(response);
  

  Basically, you have to call eval() on the response to create a javascript object. This is because the response itself is just a string when you get it back from your AJAX call. After you eval it, you have an object that you can manipulate.

  function myCallback(response) {
      var myObj = evalResponse(response);
      alert(myObj.ID1);
  }
  

  You could use a javascript library to handle this for you. Or, you could try to parse the string yourself. eval() has it's own problems, but it works.

  Joel Coehoorn : upvote for the trick using an extra assignment to stop some security vulnerabilities: if it's not assignable, the eval will just fail.

  EndangeredMassa : Thanks. It can still be worked around, but it's an extra level for a malicious user to worry about.

• Here's how you get to your data:

  <script type="text/javascript" >
  var something = [{"ID1":9996,"ID2":22}]
  alert(something[0].ID1)
  </script>
  

  EndangeredMassa : That doesn't include the response.

• It looks like an array with a single object holding two properties. I'd much prefer to see the same data structured like this:

  {"ID":[9996,22]}

  Then you have a single object holding an array with two elements, which seems to be a better fit for the data presented. Then using Endangered's evalResponse() code you could use it like this:

  var responseObj = evalResponse(response);
  
  // responseObj.ID[0] would be 9996, responseObj.ID[1] would be 22
  

• The JSON you posted represents an array containing one object, which has attributes ID1 and ID2 (initialized to the respective values after the colon).

  To convert the string to a javascript object, pass it to eval, like this:

  var obj = eval('[{"ID1":9996,"ID2":22}]');
  

  However, this method will fail if you only have a single object instead of an array, so it is safer to wrap it in parenthesis:

  var obj = eval('(' + jsonResponse + ')');
  

• If you use http://www.JSON.org/json2.js you can use it's method JSON.parse to retrieve the json string as an object (without the use of eval (which is considered evil)), so in this case you would use:

  var nwObj = JSON.parse('[{"ID1":9996,"ID2":22}]');
  alert(nwObj.ID1); //=> 9996
  

• I think the other answers might not answer your question, maybe you're looking for a way to use that "array of 1 object". Maybe this can help:

  var arr = [{"ID1":9996,"ID2":22}];
  var obj = arr[0];
  var id1 = obj.ID1;
  var id2 = obj.ID2;