# perl
my %hash; 

if ( $hash{aa}->{bb}->{cc} ) {
  print "yo\n";
}
else {
  print "no\n";
}

use Data::Dumper;
print Dumper \%hash;

^D
no
$VAR1 = {
          'aa' => {
                    'bb' => {}
                  }
        };

#