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Perl::Critic::Policy::Variables::ProhibitLoopOnHash(3) User Contributed Perl Documentation Perl::Critic::Policy::Variables::ProhibitLoopOnHash(3)

NAME

Perl::Critic::Policy::Variables::ProhibitLoopOnHash - Don't write loops on hashes, only on keys and values of hashes

VERSION

version 0.008

DESCRIPTION

When "looping over hashes," we mean looping over hash keys or hash values. If you forgot to call "keys" or "values" you will accidentally loop over both.

    foreach my $foo (%hash) {...}        # not ok
    action() for %hash;                  # not ok
    foreach my $foo ( keys %hash ) {...} # ok
    action() for values %hash;           # ok

An effort is made to detect expressions:

    action() for %hash ? keys %hash : ();                             # ok
    action() for %{ $hash{'stuff'} } ? keys %{ $hash{'stuff'} } : (); # ok

(Granted, the second example there doesn't make much sense, but I have found a variation of it in real code.)

CONFIGURATION

This policy is not configurable except for the standard options.

AUTHOR

Sawyer X, "xsawyerx@cpan.org"

THANKS

Thank you to Ruud H.G. Van Tol.

SEE ALSO

Perl::Critic

AUTHOR

Sawyer X

COPYRIGHT AND LICENSE

This software is copyright (c) 2018 by Sawyer X.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

2019-04-23 perl v5.40.0