classical_inheritance.js

// Javascript Classical Inheritance - Prototypes

function Animal (name) {
  this.name = name;
}

Animal.prototype.breathe = function () {
  return "I'm breathing";
};

Animal.prototype.say_name = function () {
  return this.name;
};

function Dog (name) {
  Animal.call(this, name);
}

Dog.prototype = Object.create(Animal.prototype);

Dog.prototype.bark = function () {
  return 'ow ow';
};

// Main
var toto = new Dog('toto');
console.log(toto.say_name());
console.log(toto.bark());

functional_inheritance.js

// Javascript Crockford's Functional Inheritance

// spec receives instance properties
function animal (spec) {
  // interface object
  var that = {};

  // Private
  function breathe () {
    return "I'm breathing";
  }

  function say_name () {
    return spec.name || '';
  }

  // Public - goes into that
  that.breathe  = breathe;
  that.say_name = say_name;

  return that;
}

function dog (spec) {
  var that = animal(spec);

  // Private
  function bark () {
    return 'ow ow';
  }

  // Public
  that.bark = bark;

  return that;
}

// Main
var toto = dog({name: 'toto'});
console.log(toto.say_name());
console.log(toto.bark());