in reply to Re: How do I access values in a hash by two different keys?
in thread How do I access values in a hash by two different keys?

It is a very good solution, thank you!
But I have a question: Why this code works 
for my $i ( keys %{ $config->{item} } ) 
{
    print $config->{item}->{$i}->{destination_dir};
}

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and this one not?
for (my $i=0; $i < 4; $i++ ) 
{
    print $config->{item}->{$i}->{destination_dir};
}

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I mean, it is nearly the same... I just say how often the loop should go and then I access via the index {$i}. Or not?
Even print $config->{item}->{1}->{destination_dir}; this one doesn't work...
I just want to understand. Thank you again!

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Re^3: How do I access values in a hash by two different keys?
by hdb (Monsignor) on Jul 19, 2013 at 09:22 UTC

    Have a look at your data structure using Data::Dumper: 

    use Data::Dumper;
print Dumper $config;

gives you

$VAR1 = {
          'item' => {
                      'AMEX' => {
                                'destination_dir' => 'test',
                                'id' => 0
                              },
                      'bla' => {
                               'destination_dir' => 'test1',
                               'id' => 1
                             },
                      'alb' => {
                               'destination_dir' => 'test2',
                               'id' => 2
                             }
                    }
        };

    [download]

    So $config->{item} represents a reference to a hash with keys "AMEX", "bla", and "alb". If you try $config->{item}->{1}->{destination_dir}; you are using a key that does not exist, the string "1".

    UPDATE: I probably should state explicitely that there is no numeric index in a hash and that there is no defined order of items in a hash that you can rely on.

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[d/l]
[select]
      Now I understand! :) Thank you very much!
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