Perl::Critic::Policy::Variables::RequireInitializationForLocalVars3pm

Write "local $foo = $bar;" instead of just "local $foo;".

Affiliation

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

Overview

Most people don't realize that a localized copy of a variable does not retain its original value. Unless you initialize the variable when you "local"-ize it, it defaults to "undef". If you want the variable to retain its original value, just initialize it to itself. If you really do want the localized copy to be undef, then make it explicit.

    package Foo;
    $Bar = '42';
    package Baz;
    sub frobulate {
        local $Foo::Bar;              #not ok, local $Foo::Bar is 'undef'
        local $Foo::Bar = undef;      #ok, local $Foo::Bar is obviously 'undef'
        local $Foo::Bar = $Foo::Bar;  #ok, local $Foo::Bar still equals '42'
    }

Configuration

This Policy is not configurable except for the standard options.

Releases

10 releases since Debian 5.0 (Lenny); the text changed 9 times.

5.0
6.0
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Arch