Re: print hash of hashes as lists

Try the following:

$evilhash->{1} = {
  red   => 1,
  blue  => 2,
  green => 3,
};
my @colors = qw( red blue green );

print join("|", @{$evilhash->{1}}{@colors}), "\n";
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The data structure you specified, the hash of hashes, would look like this:

$evilhash = {
  '1' => {
    'blue' => 2,
    'green' => 3,
    'red' => 1
  }
};
[download]

(thank you Data::Dumper)

To get to that "1" hash, you have to explicitly dereference "1" with the "->" operator because "1" is a reference to an anonymous hash. I found this in perldsc.

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Re: Re: print hash of hashes as lists by perigeeV (Hermit) on May 29, 2001 at 06:03 UTC
But that's doing the same thing. From perldsc If you want to get at the thing a reference is referring to, then you have to do this yourself using either prefix typing indicators, like `${$blah}, @{$blah}, @{$blah[$i]}` , or else postfix pointer arrows, like `$a->[3], $h->{fred}, <i>or even</i> $ob->method()->[3].` If you set the hash: `$evilhash->{1} = { ...` and deref: `@{$evilhash->{1}}{@colors})` Then that's the same as setting the hash: `$evilhash{$id} = { ...` and deref: `@{$evilhash{$id}}{@colors}` No?	[reply] [d/l] [select]
Re: Re: Re: print hash of hashes as lists by meonkeys (Chaplain) on May 31, 2001 at 03:50 UTC
First, to clarify, the answer I posted for gdig321 was not intended to represent the only Way to do it (see TMTOWTDI). I'm just used to using the -> operator. The two examples you gave are slightly different. First: `$evilhash->{1} = {}` makes $evilhash a reference to an anonymous hash. The anonymous hash has one key, "1", with an empty hashref as the value corresponding with this key. `$evilhash{1} = {}` makes %evilhash, a true hash, which has one key, "1", with an empty hashref as the value corresponding with this key. Your two examples are correctly written and will produce the same result, I agree. Thanks for the clarification, -Adam	[reply]