Keys can be used as an lvalue.
$ perldoc -f keys
...
As an lvalue "keys" allows you to increase the number of hash
buckets allocated for the given hash. This can gain you a
measure of efficiency if you know the hash is going to get big.
(This is similar to pre-extending an array by assigning a larger
number to $#array.) If you say
keys %hash = 200;
...
That said, using it as an lvalue does not magically create random keys in the
hash. It just gives the interpreter a hint on how much memory should be
allocated for it.
--Tobias
> -----Original Message-----
> From: perl-win32-users-boun...@listserv.activestate.com [mailto:perl-
> win32-users-boun...@listserv.activestate.com] On Behalf Of Aaron
> Hawryluk
> Sent: Thursday, May 03, 2012 10:23 AM
> To: Rothenmaier, Deane; perl-win32-users@listserv.ActiveState.com
> Subject: Re: Hash Key function puzzlement -- a point of information query
>
> What Leo said. keys(%hash) returns the keys from the hash as an array, you
> can't assign to it AFAIK.
>
> On Thu, May 3, 2012 at 10:18 AM, Leo Susanto <leosusa...@gmail.com>
> wrote:
> > keys is a function, it doesn't take in value
> >
> > On Thu, May 3, 2012 at 9:08 AM, Rothenmaier, Deane
> > <deane.rothenma...@walgreens.com> wrote:
> >> Gurus,
> >>
> >>
> >>
> >> Given something like this:
> >>
> >>
> >>
> >> #!Perl
> >>
> >> use strict;
> >>
> >> use warnings;
> >>
> >>
> >>
> >> my %hash; keys(%hash) = 128;
> >>
> >>
> >>
> >> print “hash has “ . scalar(keys(%hash)) . “ keys\n”;
> >>
> >>
> >>
> >> I should see a printed value of 128, wouldn’t you think? But no, it prints:
> >> “hash has 0 keys”. What’s up wit dat? What obvious thing am I missing?
> >>
> >>
> >>
> >> Thanks,
> >>
> >>
> >>
> >> Deane Rothenmaier
> >>
> >> Programmer/Analyst – IT-StdCfg
> >>
> >> Walgreens Corp.
> >>
> >> 2 Overlook Point #N51022D
> >>
> >> MS 6515
> >>
> >> Lincolnshire, IL 60069
> >>
> >> 224-542-5150
> >>
> >>
> >>
> >> The more corrupt the republic, the more numerous the laws. -- Tacitus
> >>
> >>
> >>
> >>
> >> _______________________________________________
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> >>
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