Just because you don't know where you are in the array, doesn't mean that it isn't processed sequentially. I don't know for a fact that it is, but here's my logic.

suppose you do a  foreach $element (@somearray). You're then working with $element which refrences something in @somearray. Now there's no way to tell what $element is refrencing in @somearray but that doesn't mean that the processing isn't sequential.

Rich