A brief description of the execution order of jquery Ajax _jquery

The Ajax in jquery is async by default (asynchronous request), and if you want to perform another Ajax after an Ajax execution, you need to async=false.

The code is as follows:

function Testajax ()
{
 var UserName = $ ("#txtUserName"). Val ();
 $.ajax ({
  URL: "ajaxcheckusername.htm",
  Async:false,
  success:function (data) {
   alert (data);
  }
 );
 alert (' Test ');
 $.ajax ({
  URL: "Ajaxhandler.ashx",
  async:false,
  data: "Username=" + UserName,
  success:function ( Data) {
   $ ("#divAjax"). HTML (data);
  },
  error:function (msg) {
   alert (msg.responsetext);
  }
 });
}

Then look at the jquery $.ajax. Sequence of events executed

The order of execution is as follows:

1.ajaxStart (Global event)

2.beforeSend

3.ajaxSend (Global event)

4.success

5.ajaxSuccess (Global event)

6.error

7.ajaxError (Global event)

8.complete

9.ajaxComplete (Global event)

10.ajaxStop (Global event)