sub f4 {
   for (@_) {
      print($_);
      shift;
   }
   print("\n");
}

sub f5 {
   for ((), @_) {
      print($_);
      shift;
   }
   print("\n");
}

f4(map/./g, Japh);  # Jp
f5(map/./g, Japh);  # Japh