”what if rather than iterating thru the array from the 0th element to the length of the array, you instead started from the last element and iterated backwards, until you hit zero?”
That used to be common in assembly, as it leads to smaller and faster code on many systems.
See https://stackoverflow.com/questions/2823043/is-it-faster-to-..., which also shows how times have changed, with many answers calling this premature optimization.