Something I've needed in the past was to get two arrays (odds and evens).

You can also push onto two arrays using a ternary.

knoppix@Microknoppix:~$ perl -E '
> push @{ $_ % 2 ? \ @odds : \ @evens }, $_ for 1 .. 8;
> say qq{ Odds : @odds};
> say qq{Evens : @evens};'
 Odds : 1 3 5 7
Evens : 2 4 6 8
knoppix@Microknoppix:~$
[download]

I hope this is of interest.