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Re: list assignment
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From:
Shawn H Corey
Date:
April 21, 2010 05:30
Subject:
Re: list assignment
Message ID:
4BCEEFBD.8050901@gmail.com
srd wrote:
> What really needs an explanation is if the array contains n elements
> then (n-2) warnings are emitted.
> maybe i was not so clear about my question
Paul Johnson wrote:
> On Tue, Apr 20, 2010 at 09:38:48AM -0700, Jim Gibson wrote:
>> Yes, but as srd has observed, you get one fewer warning message than
there
>> are "useless" items. Try:
>>
>> my $x = ( 1, 2 );
>>
>> and you get no warnings. Try:
>>
>> my $x = ( 1, 2, 3, 4 );
>>
>> and you get 2 warnings. One of those "useless" items isn't useless
(or Perl
>> just doesn't care).
>
> $ perl -Mdiagnostics -we 'my $x = (1,2,3)'
>
> will explain that 0 and 1 are treated specially.
>
> Using the newly released perl-5.12.0 will even tell you which of the
> constants are useless.
>
0 and 1 are special in that they don't generate the warning. For
example, the assignment to $z is the only line with warnings:
#!/usr/bin/perl
use strict;
use warnings;
my $x = ( 0, 0, 0, 0, 0, 0, 0, 7 );
my $y = ( 1, 1, 1, 1, 1, 1, 1, 7 );
my $z = ( 2, 2, 2, 2, 2, 2, 2, 7 );
__END__
--
Just my 0.00000002 million dollars worth,
Shawn
Programming is as much about organization and communication
as it is about coding.
I like Perl; it's the only language where you can bless your
thingy.
Eliminate software piracy: use only FLOSS.
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