jQuery AJAX: return a value

Question

I have this script:

function getUsername() {
    $.ajax("http://one2xs.com/index.php", {
        success: function(a) {
            console.log($(a).find("#left").html().match(/Je bent ingelogd als ([ ^A-z0-9]*)/)[1]);
            return $(a).find("#left").html().match(/Je bent ingelogd als ([ ^A-z0-9]*)/)[1];
        }
    }); 
}

alert(getUsername());

In the console log it says my username:

But the alert is 'undefined', I dont know why. I have already doing some debugging but its will not work. Does somebody know why my username works in the console log but not in the alert?

Thanks.

score 1 · Answer 1 · answered Dec 15 '13 at 10:44

1

Since it is an ajax call, it is async. So your alert is running before the call returns from the server.

Put the alert in the success function and it will work.

answered Dec 15 '13 at 10:44

Jason

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Well, its not the idea to alert the username, I alert only for testing. I need the username later. – user2897922 Dec 15 '13 at 10:46
Then you need to set that in your call back. – Jason Dec 15 '13 at 10:50

score 0 · Answer 2 · answered Dec 15 '13 at 10:52

You need to wait for the 'success' of the $.ajax call. So do something like this:

var username
function getUsernameFromServer() {
    $.ajax("http://one2xs.com/index.php", {
        success: function(a) {
            username = $(a).find("#left").html().match(/Je bent ingelogd als ([ ^A-z0-9]*)/)[1];
            console.log("got username: " + username)
        }
    }); 
}
getUsernameFromServer()

function getUsername()
  if ( username != null ) {
       return username
  } else {
       //de give it a second then try again
       setInterval(function(){
            getUsername()
       },1000);
  }
}

That is not exact, but gives you the main concept. var username is the most important part.

jQuery AJAX: return a value

2 Answers2