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Perl::Critic::PPerl::CUsercContributedaPerllDocumentationxicalLoopIterators(3)

NAME
       Perl::Critic::Policy::Variables::RequireLexicalLoopIterators - Write
       "for my $element	(@list)	{...}" instead of "for $element	(@list)
       {...}".

AFFILIATION
       This Policy is part of the core Perl::Critic distribution.

DESCRIPTION
       This policy asks	you to use "my"-style lexical loop iterator variables:

	   foreach my $zed (...) {
	       ...
	   }

       Unless you use "my", "for"/"foreach" loops use a	global variable	with
       its value "local" to the	block. In other	words,

	   foreach $zed	(...) {
	       ...
	   }

       is more-or-less equivalent to

	   {
	       local $zed
	       foreach $zed (...) {
		   ...
	       }
	   }

       This may	not seem like a	big deal until you see code like

	   my $bicycle;
	   for $bicycle	(@things_attached_to_the_bike_rack) {
	       if (
		       $bicycle->is_red()
		   and $bicycle->has_baseball_card_in_spokes()
		   and $bicycle->has_bent_kickstand()
	       ) {
		   $bicycle->remove_lock();

		   last;
	       }
	   }

	   if (	$bicycle and $bicycle->is_unlocked() ) {
	       ride_home($bicycle);
	   }

       which is	not going to allow you to arrive in time for dinner with your
       family because the $bicycle outside the loop is not changed by the
       loop. You may have unlocked your	bicycle, but you can't remember	which
       one it was.

       Lexical loop variables were introduced in Perl 5.004. This policy does
       not report violations on	code which explicitly specifies	an earlier
       version of Perl (e.g. "require 5.002;").

CONFIGURATION
       This Policy is not configurable except for the standard options.

SEE ALSO
       "Foreach	Loops" in perlsyn

       "my() in	Control	Structures" in perl5004delta

AUTHOR
       Jeffrey Ryan Thalhammer <jeff@imaginative-software.com>

COPYRIGHT
       Copyright (c) 2005-2011 Imaginative Software Systems.  All rights
       reserved.

       This program is free software; you can redistribute it and/or modify it
       under the same terms as Perl itself.  The full text of this license can
       be found	in the LICENSE file included with this module.

perl v5.24.1   Perl::Critic::Policy::Variables::RequireLexicalLoopIterators(3)

NAME | AFFILIATION | DESCRIPTION | CONFIGURATION | SEE ALSO | AUTHOR | COPYRIGHT

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