es6 syntax learning

painting/canvas.js

@@ -1,7 +1,6 @@
 import Color from "./color.js";
 
 class Canvas {
-    element;
     constructor() {
         this.element = document.createElement("canvas");
         this.element.width = 1000;

painting/rectangle.js

@@ -1,8 +1,6 @@
 import Shape from "./shape.js";
 
 class Rectangle extends Shape {
-    className = "Rectangle";
-    
     constructor(x, y, color, width, height) {
         super(x, y, color);
         

painting/shape.js

@@ -1,16 +1,13 @@
 import Color from "./color.js";
 
 class Shape {
-    className = "Shape";
-    color;
-    
     constructor(x, y, color) {
         this._x = x;
         this._y = y;
         this.color = color;
     }
     draw(context) {
-        throw new Error("A pure virtual method call of a shape " + this.className);
+        throw new Error("A pure virtual method call of a shape " + this.constructor.name);
     }
     
     static randomOptions() {