How to define a callback function in Ajax?

Your callback function will be called with the return data as a parameter automatically. It is very possible to define your callback outside the sucess: i.e. function getData () { $.ajax ( { url : 'example.com', type: 'GET', success : handleData }) } function handleData (data) { alert (data); //do some stuff }

How do I add a jQuery callback outside a success callback?

The "new" way of doing this since jQuery 1.5 (Jan 2011) is to use deferred objects instead of passing a success callback. You should return the result of $.ajax and then use the .done, .fail etc methods to add the callbacks outside of the $.ajax call.

What is Ajax jQuery?

In short; AJAX is about loading data in the background and display it on the webpage, without reloading the whole page. Examples of applications using AJAX: Gmail, Google Maps, Youtube, and Facebook tabs. You can learn more about AJAX in our AJAX tutorial. What About jQuery and AJAX? jQuery provides several methods for AJAX functionality.

Can jQuery callbacks be detached?

Flag combinations with $.Callbacks () are internally in jQuery for the .done () and .fail () functions on a Deferred — both of which use $.Callbacks ('memory once'). The methods of $.Callbacks can also be detached, should there be a need to define short-hand versions for convenience: