Javacsript ES6 class polymorphism

gistfile1.js

class Shape {
  	constructor (x,y,height,width){
  		this.x = x;
      	this.y = y;
      	this.height = height;
      	this.width = width;
  	}
  
  	draw () {
      	console.log('base draw');
  	}
}

class Circle extends Shape
{
    draw() {
        console.log('draw circle');
        super.draw();
    }
}
class Rectangle extends Shape
{
    draw() {
        console.log('draw rectangle');
        super.draw();
    }
}
class Triangle extends Shape
{
    draw() {
        console.log('draw triangle');
        super.draw();
    }
}

var variousShapes = [new Rectangle(), new Triangle(), new Circle()];

variousShapes.forEach( (shape) => shape.draw() )