Hello Monks,

I have trouble with complex data structures and I'm currently wondering why the following code doesn't work: 

use strict;
use warnings;
sub base_code (\%);

my %aas = (
'serine' => ['TCA', 'TCC', 'TCG', 'TCT'],
'proline' => ['CCA', 'CCC', 'CCG', 'CCT'] );

my %codes;
$codes{'earth'} = \%aas;
$codes{'mars'} = {
    'serine' => ['QWZ', 'QWX', 'QWW'],
    'proline' => ['ZXZ', 'ZXX', 'ZXQ', 'ZXW'] };
    
base_code (%codes); ## line 17
    
sub base_code (\%) {
    my $h_ref = $_[0];
    foreach my $planet (keys %$h_ref){
        foreach my $aa (keys %$planet){                               
+  ## line 22
            foreach my $codon (@{ $planet->{$aa} }){
                print $codon, "\n";
            }
        }
    }
}

[download]

the error message is: Can't use string ("earth") as a HASH ref while "strict refs" in use at ex9.pl line 22.

Can anyone help? Thanks in advance :)

for extra credits: Why does it complain if I write base_code (\%codes) in line 17 ? I thought it must be a reference..

In reply to printing complex data structures by ic23oluk

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