Sort hash ref of Hash of Hashes

kalyanrajsista has asked for the wisdom of the Perl Monks concerning the following question:

Monks

I'm trying to sort hash of hashes with the following code but not achieving what I want .. Here is what I've tried. Can I get one more hash reference with all sorted values...

use strict;

my $DATA = {
          '315' => {
                     'vrec' => 'ABCDE',
                     'vpay' => 'AGOUT'
                   },
          '319' => {
                     'vrec' => 'TEST2',
                     'vpay' => 'AGOUT'
                   },
          '321' => {
                     'vrec' => 'LIMCA',
                     'vpay' => 'AGOUT'
                   },
          '323' => {
                     'vrec' => 'ALBVF',
                     'vpay' => 'AGOUT'
                   },
          '325' => {
                     'vrec' => 'TEST1',
                     'vpay' => 'AGOUT'
                   },
          '313' => {
                     'vrec' => 'PQRST',
                     'vpay' => 'AGOUT'
                   }
        };

foreach (sort { $DATA->{$a}->{'vrec'} <=> $DATA->{$b}->{'vrec'} } keys
+(%{$DATA}) )
{
    print "key: $_ value: $DATA->{$_}\n"
}
[download]

Comment on Sort hash ref of Hash of Hashes Download Code

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Re: Sort hash ref of Hash of Hashes by BioLion (Curate) on Jul 06, 2010 at 10:34 UTC
You are comparing string values 'PQRST' etc... but using the numerical sort (spaceship '`<=>`') operator. You should be using cmp. See sort for more info. Just a something something...	[reply] [d/l]
Re^2: Sort hash ref of Hash of Hashes by moritz (Cardinal) on Jul 06, 2010 at 11:44 UTC
... and `use warnings;` would have warned you that Argument "PQRST" isn't numeric in numeric comparison (<=>) at .... So, always `use warnings;`. (Documented in perllexwarn).	[reply] [d/l] [select]
Re: Sort hash ref of Hash of Hashes by roboticus (Chancellor) on Jul 06, 2010 at 10:37 UTC
kalyanrajsista: You're very close: You need to use cmp instead of <=> to compare strings. Also, I changed your print statement to the following to make the result easier to check: `print "$_ ==> { vrec=$DATA->{$_}{vrec}, vpay=$DATA->{$_}{vpay} }\n +";` [download] ...roboticus	[reply] [d/l]