http://www.perlmonks.org?node_id=1034183


in reply to Scalar followed by parenthetical...

Not a bug. As $_{A} (did you mean $_->{A} perchance?), is undef, all hash keys 'B' that have a non-true value are (re)set to undef: 

C:\test>junk
Use of uninitialized value $_{"A"} in concatenation (.) or string at C
+:\test\junk.pl line 13.
$_{A} ::=>

$VAR1 = [
          {
            'A' => 1,
            'B' => undef
          },
          {
            'A' => 2,
            'B' => 2
          },
          {
            'A' => 2,
            'B' => undef
          }
        ];

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Might have expected a warning though?

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Re^2: Scalar followed by parenthetical...
by LanX (Saint) on May 19, 2013 at 02:56 UTC
    > Not a bug.

    > Might have expected a warning though?

    Since the OP's code uses strict it should die with

    Global symbol "%_" requires explicit package name at ...
Execution of ... aborted due to compilation errors.

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    Cheers Rolf

    ( addicted to the Perl Programming Language)

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      But isn't %_ immune to strict in the same way and for the same reasons as $_ and @_? 

      C:\test>perl -cmstrict -E"say %_"
-e syntax OK

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      That is, they are all 3 a part of the same typeglob.

      With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.
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