Jquery getJSON returning 'undefined'

Question

I'm trying to run a simple getJSON to a PHP file using:

$.getJSON("loadThumbs.php", { usrID: 25 }, function(data){
  alert(data.filename);
  });

And when the alert messages pops up it reads "undefined."

Here's my PHP file (loadThumbs.php):

$usrID = $_GET['usrID'];

$sql = "SELECT id, isDefaultProfile, filename, usrID FROM profile_images WHERE   isDefaultProfile=1 AND usrID='$usrID'";
$result = mysql_db_query($DBname,$sql,$link) or die(mysql_error()); 

$rows = array();

while($r = mysql_fetch_assoc($result)) {
   $rows[] = $r;
 }
print json_encode($rows);

//Which outputs: [{"id":"5","isDefaultProfile":"1","filename":"26.jpg","usrID":"25"}]

Any ideas on what I might be doing wrong?

Answer 1

Try:

alert(data[0].filename);

The JSON being returned is an array (the brackets) containing one object (the curly braces), so you have to access the first element of the array to be able to get the filename of the first file.