use strict;

my @a = qw(10 20 30);
my @b = qw( 1  2  3);

# without 'for' (implicit loop)
my @diff = map { $a[$_] - $b[$_] } 0..$#a;

print "@diff\n";  # 9 18 27

# well, without a loop, but probably not useful in the general case... ;-)
print join(" ",  $a[0]-$b[0],  $a[1]-$b[1],  $a[2]-$b[2]), "\n";