$.ajaxPrefilter() Vs $.ajaxSetup() - jQuery Ajax

Question

While learning through ajax in jQuery, I came across 2 terms, viz., $.ajaxPrefilter() and $.ajaxSetup(). All I can find out is that these

Answer 1

$.ajaxSetup simply takes an options object, and uses it as the defaults for future $.ajax() calls (and other calls that are shortcuts for this, like $.get). For instance,

$.ajaxSetup( { dataType: 'json' });

makes this the default dataType for future calls.

$.ajaxPrefilter lets you run a custom function before sending each AJAX request to the server. It can examine the options to that call, and then change them in any way that it wants. So it provides much more flexibility and control than $.ajaxSetup.