Thank you all for your answers. I understand it now. The problem with having the a complex datastructure is thatthe inormation in it will be more difficoult to access. Yes you can have methods but the methods will be more difficult to write compaired to if the information was in "normal" variables, arrays etc. I also wonder how you do to associate a object to another object? Should the object reference be added to the anonymous hash? How could that be done?