ES6 - classes

classes.js

// ES6 classes example
// ===================

// Currently, with prototypal inheritance:

var Person = function(name) {
  this.name = name;
};

Person.prototype.talk = function(words) {
  console.log(words);
}

Person.prototype.step = function(direction) {
  console.log('Stepping ' + direction);
}

Person.prototype.walk = function(steps) {
  for (var i = 0; i < steps; i++)
    this.step('forward');
}

// And in ES6 using classes. We now have constructor() and short-form
// method declaration.

class Person {
  constructor(name) {
    this.name = name;
  }

  talk(words) {
    console.log(words);
  }

  step(direction) {
    console.log('Stepping ' + direction);
  }

  walk(steps) {
    for (var i = 0; i < steps; i++)
      this.step('forward');
  }
}

// Inheritance in ES6, using super() in a method overridden.

class Troll extends Person {
  walk(steps) {
    if (steps.length > 5) throw("Too much effort");
    super(steps);
  }
}