Demonstration code for classes with properties that are other classes

Flooring.cs

namespace PropertyExample
{
    public class Flooring
    {
        public string Material { get; set; }
        public string Color { get; set; }

        public Flooring(string material, string color)
        {
            Material = material;
            Color = color;
        }
    }
}

House.cs

using System.Collections.Generic;

namespace PropertyExample
{
    public class House
    {
        public List<Room> Rooms { get; set; } = new List<Room>();
    }
}

Room.cs

namespace PropertyExample
{
    public class Room
    {
        public string Name { get; set; }
        public Flooring Floor { get; set; }

        public Room(string name, Flooring flooring)
        {
            Name = name;
            Floor = flooring;
        }
    }
}

Test.cs

using System.Collections.Generic;

namespace PropertyExample
{
    public class Test
    {
        private readonly House _testHouse = new House();

        // Contructor, populates the class-level _testHouse variable
        public Test()
        {
            // Create variables for each type of flooring
            Flooring brownCarpet = new Flooring("Carpet", "Brown");
            Flooring whiteCarpet = new Flooring("Carpet", "White");
            Flooring orangeTile = new Flooring("Tile", "Orange");
            Flooring darkBrownWood = new Flooring("Wood", "Dark Brown");

            // Populate the houuse with rooms (with flooring)
            _testHouse.Rooms.Add(new Room("Kitchen", orangeTile));
            _testHouse.Rooms.Add(new Room("Living Room", whiteCarpet));
            _testHouse.Rooms.Add(new Room("Dining Room", darkBrownWood));
            _testHouse.Rooms.Add(new Room("Master Bedroom", brownCarpet));
            _testHouse.Rooms.Add(new Room("Guest Bedroom", brownCarpet));
        }

        public List<Room> GetRoomsWithBrownCarpet()
        {
            List<Room> roomsWithBrownCarpet = new List<Room>();

            foreach(Room room in _testHouse.Rooms)
            {
                if(room.Floor.Material == "Carpet" && room.Floor.Color == "Brown")
                {
                    roomsWithBrownCarpet.Add(room);
                }
            }

            return roomsWithBrownCarpet;
        }
    }
}