using System.Collections.Generic;

using System;

/* Composition is made up of various parts that cannot exist without each other

like House must have rooms and vice versa

​

Note that Room class is nested inside House class and it is  protected!

Therefore, you cannot perform any actions directly inside Room class

But you can use Room class to perform actions inside House class

​

*/

​

​

public class Program

{

    public static void Main()

    {

        var house = new House ();

        house.AddRoom("bathroom");

        house.Display();

        house.RoomCount();

    }

}

​

​

public class House

{

    //protected list

    protected List<Room> Rooms {get;set;}

​

    //constructor

    public House ()

    {

        Rooms = new List<Room> ();

        var room1 = new Room() {Name= "Bedroom"};

        var room2 = new Room() {Name= "Living Room"};

        var room3 = new Room() {Name= "Kitchen"};

        Rooms.Add(room1);

        Rooms.Add(room2);

        Rooms.Add(room3);

    }

​

    public void Display ()

    {

        foreach (var room in Rooms)

        {

            room.Display();

        }

    }

    public void RoomCount ()

    {

        Console.WriteLine("Number of rooms: {0}", Rooms.Count);

    }

    public void AddRoom (string name)

    {

        var room = new Room () {Name = name};

        Rooms.Add(room);

    }

​

    //nested class

    protected class Room

    {

        public string Name {get;set;}

        public void Display ()

        {

            Console.WriteLine("Room name {0}" , Name);

        }

​

    }

​

​

}