Prototype model of inheritance in Javascript

prototype_example.js

/*

"In JavaScript, a prototype is a property of functions and of objects that are created by constructor functions. 
The prototype of a function is an object. Its main use is when a function is used as a constructor."
http://msdn.microsoft.com/en-us/library/hh924508(v=vs.94).aspx

"Since Javascript doesn't exactly have sub-class objects, prototype is a useful workaround to make a "base class"
object of certain functions that act as objects."
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/prototype

Here's a whimsical example ...

*/

var Dog = function() {
    this.canTalk = false;
    this.greet = function() {
        if (this.canTalk) {
            console.log("Hi, I'm a talking dog named " + this.name);
        }
    };
};

var Breed = function(n, o) {
    this.breedname = n;
    this.origin = o;
};

var welsh_springer = new Breed('Welsh Springer', 'Wales');
var lab = new Breed('Labrador Retriever', 'Canada');

Breed.prototype = new Dog();

var Pet = function(n, a, g) {
	this.petname = n;
	this.age = a;
	this.gender = g;
};

Pet.prototype = new Breed();

var Talking_Pet = function(canTalk) {
	this.canTalk = true;
};

Talking_Pet.prototype = new Breed();

/* now see what happens */

var ava = new Pet('Ava','9', 'female');
ava.prototype = welsh_springer;

var jack = new Pet('Jack', '3', 'male');
jack.prototype = lab;

var joe = new Talking_Pet();
joe.name = 'Joe';

console.log(ava);
console.log(jack);
console.log(ava.prototype);
joe.greet();

/*
{ petname: 'Ava',
  age: '9',
  gender: 'female',
  prototype: { breedname: 'Welsh Springer', origin: 'Wales' } }
{ petname: 'Jack',
  age: '3',
  gender: 'male',
  prototype: { breedname: 'Labrador Retriever', origin: 'Canada' } }
{ breedname: 'Welsh Springer', origin: 'Wales' }
Hi, I'm a talking dog named Joe
*/