@array1 = (1, 2, 3); @array2 = (4, 5, 6, 7); AddArrays( \@array1, \@array2); sub AddArrays { my ($array1, $array2) = @_; $len2 = @$array2; for( $i = 0; $i < $len2; $i++) { $array1->[$i] += $array2->[$i]; } }