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

I have some hashes that look like: 
my (%hash1, %hash2, %hash3);
my %hash_names = ( "%hash1" => "Hash One",
                   "%hash2" => "Hash Two",
                   "%hash3" => "Hash Three" );

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I also have a subroutine that I would call like this: 
&subroutine(\%hash1, "Hash One");

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I would like to call it like: 
foreach $key (sort keys %hash_names) {
    &subroutine($key, $hash_names{$key});
}

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but I cant seem to work it out. Any pointers?

nega

Replies are listed 'Best First'.
Re: Using a hash key as another hash's name...
by merlyn (Sage) on Sep 03, 2000 at 04:28 UTC
    That's almost never a good idea. What you want is to use a hash of hashrefs, then key off that. 
    my %data;
$data{"hash1"} = \%hash1;
$data{"hash2"} = \%hash2;
$data{"hash3"} = \%hash3;
...
for (sort keys %data) {
  subroutine($_, $data{$_});
}

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    The subroutine will see the hashref, so dereference it to get at the rest of the data. And if you really don't need %hash1 by name then, even simpler! 
    my %data;
$data{"hash1"} = { key1 => 25, key2 => 19, ... };
$data{"hash2"} = { key5 => 12, key8 => 'hi', ... };
$data{"hash3"} = { fred => 'flintstone', barney => 'rubble' };

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    See perllol and perldsc and perlref for more info.

    -- Randal L. Schwartz, Perl hacker

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      Came in tonight to pick up my laptop so I could bring this monster back to the couch im living on and work on it overnight. My post and your reply were still up on my monitor and I took a quick look at both and suddenly realized what I was doing wrong and what exactly your reply meant. So I swapped my keys and values, stopped refering to the new 'value' as a string, and swapped $_ and $data{$_} in the subroutine call and everything was perfect. Guess I just needed another set of eyes. Thanks!
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