Ok, i hadn't thought of it that way. I was thinking strictly about the speed of map vs. for, disregarding any other overhead that may occur as a result of how they are used.

I am no guru when it comes to perl internals. But it seems like the map{} approach is still creating that additional array, but its just hidden away - not named. I say this because (i assume) sort will need the full array that map is creating, and that array is stored somewhere - albeit internally.

That is something im still a bit uncertain of in regard to this.