class MaterialBox {
  constructor (width, length, height, weight, material, color) {
	this._width    = width;
	this._length   = length;
	this._height   = height;
	this._weight   = weight;
	this._material = material;
	this._color    = color;
  }

  get width () {
	  return this._width;
  }
  set width (width) {
	  this._width = width;
  }
  get length () {
	  return this._length;
  }
  set length(length) {
	  this._length = length;
  }
  get height () {
	  return this._height;
  }
  set height(height) {
	  this._height = height;
  }
  get material () {
	  return this._material;
  }
  set material(material) {
	  this._material = material;
  }
  get color () {
	  return this._color;
  }
  set color(color) {
	  this._color = color;
  }
  get volume() {
	 return this._width * this._length * this._height;
  }
}

var birthdayPresent = new Box(20,35,15,0.2,'paper','red');
console.log(birthdayPresent);