use strict;
use warnings;

my @array = (1,2,3,4,5);

foreach my $num (@array)
{
    $num += 5;  # completely legal
                # but obscure
}
print "@array\n"; #6 7 8 9 10

@array = (1,2,3,4,5);
@array = map{$_+5}@array;
print "@array\n"; #6 7 8 9 10