Current Perl documentation can be found at perldoc.perl.org.

Here is our local, out-dated (pre-5.6) version:

You can use this if you care about the index:

    for ($i=0; $i < @array; $i++) {
        if ($array[$i] eq "Waldo") {
            $found_index = $i;
            last;
        }
    }

Now $found_index has what you want.