using System;

​

abstract class User

{

    public string FirstName { get; set; }

    public string LastName { get; set; }

    public int UserId { get; set; }

​

    public User(string firstName, string lastName, int userId)

    {

        FirstName = firstName;

        LastName = lastName;

        UserId = userId;

    }

​

    public void DisplayUserInfo()

    {

        Console.WriteLine($"Nom de l'utilisateur : {FirstName} {LastName}");

    }

}

​

abstract class Commande : User

{

    public int CommandeNumber { get; set; }

​

    public Commande(string firstName, string lastName, int userId, int commandeNumber)

        : base(firstName, lastName, userId)

    {

        CommandeNumber = commandeNumber;

    }

​

    public void DisplayCommandeInfo()

    {

        Console.WriteLine($"Numéro de commande lié à l'utilisateur (ID {UserId}) : {CommandeNumber}");

    }

}

​

class Program

{

    static void Main()

    {

​

        CommandeNonAbstrait commande = new CommandeNonAbstrait("Joe", "Mama", 1, 6969);

​

        commande.DisplayUserInfo();

        commande.DisplayCommandeInfo();

    }

}

​

class CommandeNonAbstrait : Commande

{

    public CommandeNonAbstrait(string firstName, string lastName, int userId, int commandeNumber)

        : base(firstName, lastName, userId, commandeNumber)

    {

    }

}

​