Question

This is more a question of procedure than anything else. I’m curious why this happens and I can’t seem to find any documentation on this “feature” within the ECMA script documentation.

When I make an AJAX call within jQuery to my server, it returns the following JSON response to the page:

{"version":"v1","status":"OK","timestamp":"2013-02-14 10:32:45","data":"true","error":""}

With this string I have to call jQuery.parseJSON(string); to get it as an object, and the be able to reference it as an object.

However, when my server returns something like this:

{"version":"v1","status":"OK","timestamp":"2013-02-14 10:12:19","data":{"a":"asgsadfga","b":false,"c":[]},"error":""}

Javascript automatically loads this an an object without the need to parse. It would seem that because this example returns a nested object, despite the fact it was returned from the server as a string, Javascript will immediately recognize that, and parse the string for me.

Is this expected functionality, and if so, can anyone point me to the documentation of this?

EDITED:

Here is the offending AJAX call:

    jQuery.ajax({
        url: url,
        type: 'GET',
        async: false,
        success: function (result) {
            console.log(result)
        }

Answer 1

According to ajax() in jQuery API Documentation under dataType:

dataType (default: Intelligent Guess (xml, json, script, or
html))Type: String The type of data that you’re expecting back from
the server. If none is specified, jQuery will try to infer it based
on the MIME type of the response (an XML MIME type will yield XML, in
1.4 JSON will yield a JavaScript object, in 1.4 script will execute the script, and anything else will be returned as a string).

Hope this helps.