在jQuery（或Javascript）中，如何获得“最顶层”元素？

I have a list of elements (with class "newsitem"), that are available throughout the page. I want the highest element, that is the element with the lowest "top" value from that class. How do I get in jQuery efficiently, right now I'm working on iterating through the newsitem class, storing the top value and comparing it with the lowest value so far. Is this pretty much the only way to do it or is there an actual method?I have a list of elements (with class "newsitem