static void Main(string[] args)
{
User user1 = new YouthUser {
Name = "Jane"
};
User user2 = new YouthUser {
Name = "Ron"
};
User user3 = new AdultUser {
Name = "Zoe"
};
User user4 = new AdultUser {
Name = "Wendy"
};
InterestsGroup book = new Book();
InterestsGroup music = new Music();
user1.Accept(book);
user1.Accept(music);
user2.Accept(book);
user3.Accept(music);
user4.Accept(music);
book.Display();
Console.WriteLine();
music.Display();
}
public override void VisitYouthUser(YouthUser youthUser) => youthUsers.Add(youthUser);
public abstract void VisitYouthUser(YouthUser youthUser);