$ .ajax是否替换$（document）.ready（function（）？

Question

I 've made a thorough search, however I cannot find something clear about my assumption. I 've used the following code:

<?php  
session_start();
if (isset($_SESSION['valid_user']) && $_SESSION['from']==1)
{
 ?>
    <script type="text/javascript"> 
        $.ajax({
        method:"POST",
        dataType: 'json',
        url:"user.php",
        success: function(newdata) {
             if (newdata == "nothing")
            {
               var temp1 ="no data!";
               $("#results_ribbon").text(temp1);              
               return;
            }
            var temp1 ="You have: ".concat(newdata);
            $("#results_ribbon").text(temp1); 
        }   
    });
  </script>       

which is part of a php file. The HTML code which builds the DOM follows after the above code...

So, I'd expect div with id="results_ribbon" not to have the right content since #results_ribbon does not exist, yet. However, everything works fine. This led me to assume that $.ajax call waits to be executed after DOM loading. Am I right? If not why the above happens?

Answer 1

No, it's not correct. Actual Ajax request starts immediately after your call it. But success callback will fire after a while when it gets the server response. By that time you already have your #results_ribbon loaded in DOM.