如何在Perl中仅取消引用数组散列的散列？

Question

{    
    'A' =>      ['B'], //hash of array   
    'C' => {'D' => [  'E']} //hash of hash of array    
}

When try to parse hash of hash of array. getting "Not a HASH reference" error. Even I tried used exists and defined keywords to avoid this error. But result is same error.

From above i need to only iterate hash of hash of array.

foreach my $keys (keys %$hash){
        print "$keys";
     if (defined $hash->{$keys}->{maptype}){
            foreach my $array_element ( @{$hash->{$keys}->{'D'}} ) {
                        print "$array_element"); 
            }
        }
    }

Answer 1

Not sure if this is best practice, but:

my $hash = { A => ['B'], C => {D => ['E'], F => [qw(G H I)]}, J=>42 };

for my $key (keys %$hash) {
    if (ref $hash->{$key} eq 'HASH') {
        for my $subkey (keys %{$hash->{$key}}) {
            say "$key => $subkey => [", join(",", @{$hash->{$key}{$subkey}}), "]";
        }
    }
}

outputs

C => D => [E]
C => F => [G,H,I]