What is the exact rule of jQuery's animate() parameters?
- by Jian Lin
jQuery 1.4.2's animate() API spec is
.animate( properties, [ duration ], [ easing ], [ callback ] )
but it seems that we can supply duration, callback, and no easing
.animate({left: '+= 100'}, 600, doThis)
and it will work.
But if we supply easing and callback and no duration
.animate({left: '+=100'}, 'swing', doThis)
then the easing won't be taken into effect. So what exactly is the API supposed to be?