1.22 d4.pl

$a = sum(3,4,5);
print "$a\n";

my $result = factorial(5),"\n";
print "$result\n";


sub sum {
  my $sum = shift @_;
  if (@_) {
     $sum += sum(@_);
  }
  return $sum;
}

sub factorial {
  my $n = shift;
  if ($n == 1 or $n == 0) {
     return 1;
  }
  my $total = $n * factorial($n-1);
  return $total;
}