How to get the json return value

Question

If I can get the following string

([{"data":{"id":"1","user_name":"tutor","book":"123","role":"Tutor"}}]);

How can I alert it? data.user_name show undefined.

    $.getJSON('http://mydomain.com/getmyDetail.php?jsoncallback=?', function(data) {   
        alert(data.user_name);    
    });
    }

another question, if I would like to put some value to the URL, such as

http://mydomain.com/getmyDetail.php?username=XXX&role=XXX

, how to put into getJSON function, directly

$.getJSON('http://mydomain.com/getmyDetail.php?username='+username'+'&role='+role+'&'jsoncallback=?' ?

Answer 1

The [{ means that this is nested in a single element array. On top of that, the highest level key of the element is data. Use:

alert(data[0].data.user_name);

Answer 2

In your example, data is the variable name for the whole response, and you need the user_name element inside the data element, so you should probably try something like

alert(data[0].data.user_name);