Getter/Setters with ES5/ES6 in TypeScript

app.ts

// ES5
var Element = (function() {
  function Element() {
    this._class = null;
  }
  Object.defineProperty(Element.prototype, 'className', {
    get: function() {
      return this._class;
    },
    set: function(name) {
      this._class = 'todd-' + name;
    },
    enumerable: true,
    configurable: true,
  });
  return Element;
})();


//ES6
export class Element {
  private _class: string = null;

  get className() {
    return this._class;
  }

  set className(name) {
    this._class = `todd-${name}`;
  }
}