根据开发人员用CSS指定的内容，是否可以使用jQuery以百分比或像素为单位获取元素的宽度？

I'm writing a jQuery plugin and something I need to be able to do is determine the width of an element that the user specifies. The problem is that .width() or .css('width') will always report exact pixels, even if the developer has assigned it e.g. width:90% with CSS. I'm writing a jQuery plugin and something I nee