SPUG: last index array reference's referent

Michael R. Wolf MichaelRWolf at att.net
Mon Jan 22 17:51:36 PST 2007


Thanks.

I didn't believe that this was documented.  I still don't.  But perhaps this
is as close as it gets.  (Put on your Perl glasses, and read between the
lines.)  I can make myself believe that this is what it means, but I'd have
been hard pressed to realize it up front.  Thanks again!

I guess I like it that Perl anticipated my needs here..??!!..

http://perldoc.perl.org/perlref.html#Using-References-reference%2c-use-deref
erencing-dereference

Using References

That's it for creating references. By now you're probably dying to know how
to use references to get back to your long-lost data. There are several
basic methods.

   1.

      Anywhere you'd put an identifier (or chain of identifiers) as part of
a variable or subroutine name, you can replace the identifier with a simple
scalar variable containing a reference of the correct type:

          $bar = $$scalarref;
          push(@$arrayref, $filename);
          $$arrayref[0] = "January";
          $$hashref{"KEY"} = "VALUE";
          &$coderef(1,2,3);
          print $globref "output\n

[... See link for full details]



-- 
Michael R. Wolf
    All mammals learn by playing!
        MichaelRWolf at att.net

> -----Original Message-----
> From: spug-list-bounces+michaelrwolf=att.net at pm.org [mailto:spug-list-
> bounces+michaelrwolf=att.net at pm.org] On Behalf Of jerry gay
> Sent: Sunday, January 21, 2007 3:45 PM
> To: Michael R. Wolf
> Cc: spug-list at mail.pm.org
> Subject: Re: SPUG: last index array reference's referent
> 
> On 1/21/07, Michael R. Wolf <MichaelRWolf at att.net> wrote:
> > # Is there a more elegant way to get the equivalent of $#seasons if
> > # all you have is a reference?  Somehting that would do to references
> > # what $# does to arrays....
> >
> sure! use C<$#$seasons>
> 
> perl -Mstrict -Mwarnings -e'my $a=[1,2,3]; print $#$a;'
> 2
> 
> ~jerry
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