ES6 OOP Example

index.js

'use strict'
const Rocket = require('../lib/Rocket');
const Missile = require('../lib/Missile')

var apollo13 = new Rocket('Apollo', 'Moon', 1993);

var mach10 = new Missile(1000000, 2016);

console.log(mach10.year);

Missile.js

'use strict'

const Rocket = require('./Rocket.js');


module.exports = class Missle extends Rocket {
  constructor( speed, year ) {
    super('Mach 10', 'North Korea', year)
    this._speed = speed;
  }

  get speed() {
    return this._speed;
  }
}

Rocket.js

'use strict'

var Vehicle = require('./Vehicle.js');

module.exports = class Rocket extends Vehicle {

  constructor( model, destination, year ) {
    super( year, 'Red' );
    this._model = model;
    this._destination = destination;
    this.fuel = 100;
    this._launchCount = 0;
  }

  get destination() {
    return this._destination;
  }

  set destination( place ) {
    if (typeof place !== 'string') {
      throw new TypeError('Rocket.destination must be a string')
    }
    this._destination = place;
  }

  launch() {
    this._launchCount++;
    console.log('TO THE MOON');
  }
}

Vehicle.js

'use strict'

module.exports = class Vehicle {
  constructor ( year, color ) {
    this._year = year;
    this._color = color;
  }

  get year() {
    return this._year;
  }

  set year(year) {
    if (typeof year !== 'number') {
      throw new TypeError('Vehicle.year must be a number')
    }
    this._year = year;
  }
}