in reply to HoH Weirdness

Somehow I think you're not using strict.

On my machine $hash{ 'key1' }{ 'key2' } gives me a compilation time error with strict

Perhaps you meant $hash{ 'key1' }->{ 'key2' } ?

Either way, do this to verify if your hashes are working the way you want them to...

      use Data::Dumper;
      print Dumper( \%hash );

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This is quick and dirty, but at least you get to do a sanity check as to what's in the hash...

----

update: added explanation in a separate node upon request :)

update: a few people have gotten me. for those of you reading my posts in this thread, please make sure to read these two posts, cause I screwed up. :(

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Re: Re: HoH Weirdness
by John M. Dlugosz (Monsignor) on Jun 09, 2001 at 00:19 UTC
    Perhaps you meant $hash{ 'key1' }->{ 'key2' } ?

    Care to continue that thought with an explaination of how 

    $hash{ 'key1' }->{ 'key2' }

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    is different in meaning from 
    $hash{ 'key1' }{ 'key2' }

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    ?
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[d/l]
[select]

      As everybody else says, 

           $hash{ 'key1' }{ 'key2' }

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      takes the contents of $hash{ 'key1' } to be a symbolic reference, and then tries to get the value of that corresponds to 'key2' against a hash with the name = $hash{ 'key1' }

      So

           $hash{ 'key1' } = 'foo';
     $hash{ 'key1' }{ 'key2' } = 'bar'; # (2)

     # (2) means find %(current pkg)::foo and do
     $(current pkg)::foo{ 'key2' } = 'bar';

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      Still a hash of hashes, but I find this rather tricky to use. You always have to be aware of the fact that $hash{ 'key1' }{ 'key2' } is being evaluated via symbols

      However, $hash{ 'key1' }->{ 'key2' } would be used like this:

           my %hash;
     $hash{ 'key1' } = {}; ## ref to hash

     $hash{ 'key1' }->{ 'key2' } = 'foo';

     ## above equivalent to
     my %hash = (
           key1 => {
                  key2 => 'foo'
           }
     );

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      And, of course, I wrote up to here and realized that it doesn't really fit to the original problem! sigh.

      I probably should have pointed to

             $hash{ 'key1' } = 'foo';
       $hash{ 'key1', 'key2' } = 'bar';

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      But I really dislike that notation. ( and the way things gets stored when you do it that way )

      As for the original problem, I would have done:

      
       my %hash = (
             food => {
                   name => 'Apple',
                   color => 'Red'
             }
       );

       my $food = $hash{ 'food' };
       print "$food->{ 'color' } $food->{ 'name' }\n";

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      Is this explanation better ? :-)

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[d/l]
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        I think a review of perlref is in order. $hash{ 'key1' }{ 'key2' } and $hash{ 'key1' }->{ 'key2' } are exactly equivalent.

        ->, the dereferencing operator, is optional between subscripts.

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[d/l]
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        No, I still wonder. Perlref says "The arrow is optional between brackets subscripts" so I don't see how explicitly putting the arrow in makes the compiler do things differently -- it still needs the first subscript to return a reference, and it doesn't matter whether it's symbolic or not.
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