http://www.perlmonks.org?node_id=1048624


in reply to Getting Keys From Hash In a Hash

Like this:

my %form; my %field = ( 'key 1' => 'value 1', 'key 2' => 'value 2', ); $form{another_hash} = \%field; for my $first_key ( keys %form ) { for my $hoh_keys ( keys %{ $form{$first_key} } ) { print $hoh_keys, $/; ## get the keys } }
You can also check perldsc. or **Specifically: Access and Printing of a HASH OF HASHES
You really can use Data::Dumper to see how the data structure looks like, then you can get at what you want.
use Data::Dumper; ... print Dumper \%form;
produces..
$VAR1 = { 'another_hash' => { 'key 2' => 'value 2', 'key 1' => 'value 1' } };
** Updates.

If you tell me, I'll forget.
If you show me, I'll remember.
if you involve me, I'll understand.
--- Author unknown to me

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Re^2: Getting Keys From Hash In a Hash
by HalNineThousand (Beadle) on Aug 08, 2013 at 19:25 UTC

    Thank you!

    My mistake was that when I used this:

    keys %{ $form{$first_key} }
    I was leaving out the $ in front of form, like this:
    keys %{ form{$first_key} }

    So I at least remembered some of what I was doing - forgot how to treat it within the brackets.