for (my $i=0; $i<@CD_new_a_v_d_D; $i++) {
        if ($key eq $CD_new_a_v_d_D[$i]) {
            print "$key - $value\n";
        }
    }

##</code><code>##

    for (@CD_new_a_v_d_D) {
        if ($key eq $_) {
            print "$key - $value\n";
        }
    }

##</code><code>##

    for (0 .. $#CD_new_a_v_d_D) {
        if ($key eq $CD_new_a_v_d_D[$_]) {
            print "$key - $value (at $_)\n";
        }
    }