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searching for empty keys in multidimensional hash

pearl0817
New User

Aug 17, 2011, 7:57 AM

Post #1 of 3 (895 views)

searching for empty keys in multidimensional hash	Can't Post

Hello,
This is my first time posting here. I have researched this prior to posting, but couldn't find any solution. I need to clean up hashes stored in our database. Some of them have empty keys, so those have to be deleted. Here's a sample hash:

Code

'Groups' 
{ 
  'A' => { 
    '' => '45', 
    'allMembers' => '46,69,45' 
  }, 
  'B' => { 
    'BO' => '52', 
    'allMembers' => '52' 
  }, 
  'D' => { 
    'Dive Ops' => '105', 
    'Diving' => '274', 
    'allMembers' => '105,274' 
  }, 
  'F' => { 
    'FO' => '276', 
    'allMembers' => '276' 
  }, 
  'SP' => { 
    'SP' => '275', 
    'allMembers' => '275' 
  }, 
  'rt' => { 
    '' => '91', 
    'allMembers' => '119,91' 
  } 
}

So taking the first set as an example

Code

'A' => { 
    '' => '45', 
    'allMembers' => '46,69,45' 
  },

The first value has an empty key,it has to be deleted, and then since there are no more items actually, A has to be deleted altogether. I have a problem with syntax,how do I loop through this hash and single out the empty keys?
Any help would be greatly appreciated.
Thanks!

BillKSmith
Veteran

Aug 17, 2011, 8:45 PM

Post #2 of 3 (873 views)

Re: [pearl0817] searching for empty keys in multidimensional hash [In reply to]	Can't Post

Looping is straightforward. Doing all the dereferencing correctly is another matter. Half the trick is making reasonable names for the new variables. I hope that I have succeeded.

Code

use strict; 
use warnings; 
use Data::Dumper; 
my $Groups = { 
    A => { 
        ''           => '45', 
        'allMembers' => '46,69,45', 
    }, 
    B => { 
        'BO' => '52', 
        'allMembers' => '52' }, 
    D => { 
        'Dive Ops'   => '105', 
        'Diving'     => '274', 
        'allMembers' => '105,274', 
    }, 
    F  => { 
        'FO'         => '276', 
        'allMembers' => '276', 
    }, 
    SP => { 
        'SP'         => '275', 
        'allMembers' => '275', 
    }, 
    rt => { 
        ''           => '91', 
        'allMembers' => '119,91', 
    }, 
};  
 
foreach my $sub_groups (values %$Groups) { 
    foreach my $member (keys %$sub_groups) { 
        delete $sub_groups->{$member} if !$member; 
    } 
}  
 
print Dumper $Groups;  
 
while (my ($group_name, $sub_groups) = each %$Groups) { 
    delete $Groups->{$group_name} if  1 >= scalar keys %$sub_groups ;  
}  
 
print Dumper $Groups;

Good Luck,
Bill

pearl0817
New User

Aug 18, 2011, 9:26 AM

Post #3 of 3 (870 views)

Re: [BillKSmith] searching for empty keys in multidimensional hash [In reply to]	Can't Post

Bill, Thanks a bunch! Your solution works perfectly. I was SO lost :)
Thanks again
Victoria

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