Question

I know that we can have the absolute position of a div even if we don’t set it (by using offset) : http://www.quirksmode.org/js/findpos.html

Can we get the width (or height) of a div even if we don’t specify it ?

Answer 1

You can use clientWidth and offsetWidth to get the width.

var foo = document.getElementById('foo').clientWidth;
var foo = document.getElementById('foo').offsetWidth;

clientWidth returns the viewable width of an element but does not include borders, margins, or scrollbars. offsetWidth returns the width of an element (including borders and padding), but not margins.