my $primaryFeatures = { 
    'foo', ('fool', 'food', 'foot'), 
    'bar', ('barricade'), 
}; 
 
while (my ($key, $value) = each(%$primaryFeatures)){ 
   print "($key, $value)\n"; 
}

use strict; 
use warnings; 
my $primaryFeatures 
    = { foo => [ 'fool', 'food', 'foot' ], 
        bar => ['barricade'], 
      }; 
while ( my ( $key, $hash_value ) = each(%$primaryFeatures) ) { 
    foreach my $array_element (@$hash_value) { 
        print "($key, $array_element)\n"; 
    } 
}