clases en javascript

clases.js

/* jshint esnext: true */
// class ES6 
class Button {
  constructor(label, callback) {
    this.label = label;
    this.callback = callback;
    this.html = this.createHTML();
    this.bindEvents();
  }
  onClick() {
    this.callback();
  }
  bindEvents() {
    this.html.addEventListener('click', this.onClick.bind(this));
  }
  createHTML() {
    let button = document.createElement('button');
    button.innerHTML= this.label;
    return button;
  }
  getHTML(){
    return this.html;
  }
  
  static compare(a, b){
    return a.label === b.label;
  }
}

class ButtonImage extends Button {
  constructor(url, callback) {
    super(null, callback);
    this.setURL(url);
  }
  setURL(url){
    this.html.src = url;
  }
  createHTML() {
    let img = document.createElement('img');
    return img;
  }
}

let button = new Button('Click', function (){
  console.log('Click !!!');
});
document.body.appendChild(button.getHTML());

let imgBtn = new ButtonImage('https://i.imgur.com/Beo1vHQ.gif', function () {
  console.log('Soy la imagen con click');
});
document.body.appendChild(imgBtn.getHTML());

let button2 = new Button('Hola', function (){
  console.log('Click !!!');
});


console.log(Button.compare(button, button2));