For those times when we want or need to exert a fine-grained level of control over how we make Ajax requests, jQuery provides a general utility function for making Ajax requests named $.ajax(). Under the covers, all other jQuery features that make Ajax requests eventually use this function to initiate the request.

$.ajax(options)

Initiates an Ajax request using the passed options to control how the request is made and callbacks notified.

Parameters

Looks simple, doesn’t it? But don’t be deceived. The options parameter can specify a large range of values that can be used to tune the operation of this function. These options (in order of the likelihood of their use) are defined in the table:

Options for the $.ajax() utility function

Examples:

Load and execute a JavaScript file.

    	$.ajax({
          type: "GET",
          url: "test.js",
          dataType: "script"
        });
    

Save some data to the server and notify the user once its complete.

    	$.ajax({
           type: "POST",
           url: "some.php",
           data: "name=John&location=Boston",
           success: function(msg){
             alert( "Data Saved: " + msg );
           }
         });
    

Retrieve the latest version of an HTML page.

	$.ajax({
      url: "test.html",
      cache: false,
      success: function(html){
        $("#results").append(html);
      }
    });

Loads data synchronously. Blocks the browser while the requests is active. It is better to block user interaction by other means when synchronization is necessary.

    	var html = $.ajax({
          url: "some.php",
          async: false
         }).responseText;
    

Sends an xml document as data to the server. By setting the processData option to false, the automatic conversion of data to strings is prevented.

	 var xmlDocument = [create xml document];
         $.ajax({
           url: "page.php",
           processData: false,
           data: xmlDocument,
           success: handleResponse
         });