passing a multidimentional hash-sub-hash (to a sub and back again)

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

i had this working at one point but it suddenly stopped
(grrr)

sub BackAndForth {     
     my ($filename) = @_;


      #  make multi-dimensional hash here ... it looks like
      #  $ALLDATA{$filename}{$key1}{$key2}{$key3} = [@array]
      
      return (%ALLDATA);     
}

      my %ExternalHash = &BackAndForth('filename.csv');
         %ExternalHash = &BackAndForth('filename2.csv');
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   now i played around with it a bit and can't remember 
   what i may have changed ... $ here, % there (yadda yadda)

   if i do a variable dump on %ALLDATA i get ...

          %ALLDATA = (
               'key1' => HASH(0x9021f6c)
                   'key2' => HASH(0x90154a8)
                       'key3' => ARRAY(0x9015400)
                                  0  value1
                                  1  value2
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   but if i do the same on %external i get

   %thisDataset = (
          '' => HASH(0x876f324)
                'key2' => HASH(0x9029220)
                       empty hash)
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       looking at the memory locations, we can see that 
       they're not the same hashes (but that should be 
       obvious cause i'm getting the return of a strange 
       set of data)

       where is the garbage coming from ?
            prehaps

       return(\%ALLDATA)
       %external = (yadda yadda)
             or 
       $external = (blah ...
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Comment on passing a multidimentional hash-sub-hash (to a sub and back again) Select or Download Code

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RE: passing a multidimentional hash-sub-hash (to a sub and back again) by Buckaroo Buddha (Scribe) on Jun 30, 2000 at 18:52 UTC
</code> FYI it's return(\%ALLDATA) $external = (blah blah blah) foreach $newkey (sort keys %$external) { #travels through the first level of that hash... } yes, i posted and answered my own question ... leave me alone ;) it's good for the FAQ i'd liek to know why it does that though	[reply]
Re: passing a multidimentional hash-sub-hash (to a sub and back again) by ase (Monk) on Jul 01, 2000 at 00:34 UTC
I think the answer to your question lies in the fact that `return(%ALLDATA)` returns a list of values (the keys and values of `%ALLDATA` while `return(\%ALLDATA)`returns one value: a scalar that is a reference to the hash. Hope that helps, -ase	[reply] [d/l] [select]


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