draq wrote:
> E. g. I am going to make a programm for a forwarding agency containing
> two classes: City and Connection.
>
> The class City contains information about clients, goods etc. and the
> class Connection implies the path length, potential toll charges and
> type of the road.
>
> How can I implement the two classes the best? With both classes
> referring to each other?

Well, a connection certainly needs a starting and ending point - at least
this seems most natural.  Whether a city needs to know all its connections
depends on the application.  With that little info hard to tell...

Kind regards

    robert