in reply to Size of an Hash reference

It depends on how you populate the hash. Compare: 
use Data::Dumper;

$hashR = {};
print Dumper $hashR;

$hashR->{$x} = $y;
print Dumper $hashR

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Output:

$VAR1 = {};
$VAR1 = {
          '' => undef
        };

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لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ

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Re^2: Size of an Hash reference
by dvinay (Acolyte) on Nov 11, 2013 at 14:53 UTC

    Exactly i used the second way to populate my hash 

    $hashR->{$x} = $y;

    [download]

    reference, so is it because of this, that there is an empty key pointing to undef value

    anything wrong in populating the hash reference in above mentioned way...?

[reply]
[d/l]

      Yes, but, apparently, neither $x nor $y was defined when you did it. The remedy is probably to check that $x and $y are defined before populating the hash with these values (especially $x).

[reply]

        Thanks a lot for your help,

        i have one more doubt if i want to check the existence of an key in an hash reference

        here is this i have tried 

        print Dumper \$returnvalue;
$VAR1 = \{
            ' WWN2' => ' 5678',
            ' WWN1' => ' 125689'
          };
my $string="WWN1";
if (exists $returnvalue->{$string})

        [download]

        to my surprise its returning false

        Any clue why its happening, is my if condition correct or not
[reply]
[d/l]

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