这个房间有四面墙。如果我们假设一个长方形的房间，事情可能会变得更复杂。
最常用的方法是不假设四面墙，而只假设房间有一系列墙。

class Wall {
  final double height;
  final double width;
  Wall({required this.height, required this.width});
  double get totalArea => height * width;
}
class Room {
  final List<Wall> walls;
  Room(Iterable<Wall> walls) : walls = List.unmodifable(walls);
}

void main() {
  var room = Room([
    Wall(width: 4, height: 4),
    Wall(width: 2, height: 4),
    Wall(width: 4, height: 4),
    Wall(width: 2, height: 4),
  ]);
  var wallArea = 0.0;
  for (var wall in room.walls) wallArea += totalArea;
}

这允许任何墙壁组合，为您的基本L形房间与六面墙，或七边形房间的风格。
在某些情况下，你可以通过假设来使事情变得更容易。就像一个长方形的房间总是有相同的相对的墙壁，并且到处都有相同的高度。
然后您可以：

class RectangularRoom implements Room {
  final double length1;
  final double length2;
  final double height;
  final List<Room> rooms;
  RectangularRoom({
      required this.length1, 
      required this.length2, 
      required this.height}) 
      : rooms = _createWalls(length1, length2, height);
  static List<Room> _createWalls(
      double length1, double length2, double height) {
    var wall1 = Wall(length: length1, height: height);
    var wall2 = Wall(length: length2, height: height);
    return List.unmodifiable([wall1, wall2, wall1, wall2]);
  }
}

或者，您可以假设房间以某种方式定向：

// Also assumed rectangular.
class OrientedRoom extends Room {
  final Wall northWall;
  final Wall westWall;
  final Wall southWall => northWall;
  final Wall eastWall => westWall;
  OrientedRoom({
      required double length1, 
      required double length2, 
      required double height
  }) : this._(Wall(length: length1, height: height), 
              Wall(length: length2, height: height));

  OrientedRoom._(this.northWall, this.westWall) 
      : super([northWall, westWall, northWall, westWall]);
}

这允许您命名各个墙，并为每个墙提供一个class字段。
这么多的选择，哪一个适合你取决于你的用例，你将使用对象做什么。

就像@Dimon在评论中说的，你可以通过为你想要在房间里的每一面墙添加一个属性来管理它。
大概是这样的

class Room {
  final Wall leftWall;
  final Wall rightWall;
  final Wall topWall;
  final Wall bottomWall;

  Room(this.leftWall, this.rightWall, this.topWall, this.bottomWall);

}

并按如下方式创建您的文件室：

var room = Room(Wall(height: 15, width: 20), Wall(height: 15, width: 8),
        Wall(height: 15, width: 3), Wall(height: 15, width: 22));