On Fri, Oct 18, 2013 at 11:09 AM, James Greene <[email protected]> wrote: > I would also love to see `getElementById` added to the HTMLElement/Element > interface. It would be nice to capitalize on that potential perf boost in > jQuery as well.
There's no perf boost available for searching by id on an arbitrary element. The reason you may get a better perf for the normal functions is that documents cache a map from id->element on themselves, so you just have to do a fast hash-lookup. Arbitrary elements don't have this map (it would be way too much memory cost), so it'll fall back to a standard tree search, exactly as a querySelector would. ~TJ
