How to know when jquery effect ends if there are several elements that are animated

Question

In the following example: If 5 <li> elements are found, the callback raises a warning 5 times ...

Is there an easy way to find out when the animation is really finished and only fire once ?

 $(this).parent().siblings('li').slideUp(500,function(){ alert }); 

Answer 1

 $.when($(this).parent().siblings('li').slideUp(500)) .then(function() { alert('Finished!'); }); 

Working demo

when docs :

Description: Provides a way to perform callback functions based on one or more objects, usually deferred objects representing asynchronous events.