my $ma = {
    first=>'Morticia', last=>'Addams', age=>undef, favorite_color=>'black',
    address=>{ street_num=>131313, street_name=>'Mockingbird Lane', 
               city=>'Perish', st=>'NY', zip=>13131 
    },
};

my $white_house = {
    class=>'GOVT', branch=>'Executive', usage=>'Presidents Residence', ...
    address=>{ street_num=>1600, street_name=>'Pennsylvania Avenue, N.W.', 
               city=>'Washington', st=>'DC', zip=>20500 
    },
};

print_address($ma->{address});
print_address($white_house->{address});

sub print_address {
    my $addr = shift;
    print "$addr->{street_num} $addr->{street_name}\n$addr->{city} $addr->{st} $addr->{zip}\n";
}