empty-checking loop end — .until(null / $ ,loopContext)

`.until(null / $ ,loopContext)`

Description: The end for a repeat loop that finishes if the calling jQuery context is empty.

null / $ – undefined or the jQuery token, optional: If null or missing then the loopContext parameter defaults to false.; If $ is used then loopContext defaults to true.
loopContext – boolean, optional: if true then the current jQuery context starts the next loop iteration. Otherwise the original context from the .repeat() call is used for each iteration.

Tip: For short code use .until($) instead of .until(null,true),
and .until() instead of .until($,false).

Given that you have a method which selects any element from the current jQuery set randomly,
e.g.

$.fn.random = function(){ return this.eq(
  Math.floor(Math.random()*this.length)) }

,
then you can use that to build a banner rotator very easily.

In this example there are four different banners. Every 5 seconds another one fades in, randomly chosen.

As we don't want to wait for the animations finishing we use the original version of .fadeIn() and .fadeOut() here.

$('#banners > *').hide().repeat(5000,true)
   .fadeOut(1000).siblings().random().fadeIn(1000)
.until($);

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