Question

I want to animate a div from top down. I think the idea is animate the height from 0 to its rendered width.
But before it is shown I don’t know the rendered width, how to write the code to animate this?

It’s like: $.animate({"width":"auto"})

Answer 1

You need to grab the width using .width() like so:

var $el = $("#elementID");
$el.animate({height: $el.width()});