Re: RFC 120 (v1) Implicit counter in C<for> statements, possibly C<$#>.

On 16 Aug 2000, Perl6 RFC Librarian wrote:

> This and other RFCs are available on the web at
>   http://dev.perl.org/rfc/
> 
> =head1 TITLE
> 
> Implicit counter in C<for> statements, possibly C<$#>.
> 
> =head1 VERSION
> 
>   Maintainer: John McNamara <[email protected]>
>   Date: 16 Aug 2000
>   Version: 1
>   Mailing List: [email protected]
>   Number: 120
> 

> However, the latter format is often more convenient if you need to keep track of the array index as well as iterating over the array:
> 
>     for ($i = 0; $i <= $#array; $i++) {
>         print $array[$i], " is at index ", $i, "\n";
>     }
> 
> is more succinct than:
> 
>     $i = 0;
>     foreach $item (@array) {
>         print $item, " is at index ", $i, "\n";
>         $i++;
>     }
> 

What about:

     for (0..$#array) {
         print $array[$i], " is at index ", $i, "\n";
     }

I use that whenever I need to loop over indices of two arrays at once.

-- 
Tim Jenness
JCMT software engineer/Support scientist
http://www.jach.hawaii.edu/~timj