#!/usr/bin/perl

use strict;
use warnings;

# Effect a "join" with ", "
local $"=', ';#"
# Use the baby cart so we can call even / odd within quotes to exploit $"
print "@{[even(1,2,3,4)]} are even\n while @{[odd(1,2,3,4)]} are odd\n";
exit;

# Note the use of prototypes so we can pass the list and the desired remainder without flattening
sub EvenOrOdd (\@$) {
    my ($numbers,$remainder)=@_;
    return grep { $_ % 2 == $remainder } @$numbers;
     };

sub even {
    EvenOrOdd(@_,0);
     };
sub odd {
    EvenOrOdd(@_,1);
     };