gistfile1.js

// Let's create a class with some abstract methods

var Animal = Class.extend({
	
	init: function() {
		console.log('A new', this.name, 'is born!')	
	},
	
	talk: function() {
		console.log('The', this.name, 'goes', this.action)
	}
})


// Now let's extend our abstract class

var Cat = Animal.extend({
	name: 'cat',
	action: 'miaow'
})

var Kitten = Cat.extend({
	name: 'kitten'
})

var Dog = Animal.extend({
	name: 'dog',
	action: 'woof'
})


// Now, let's generate some new objects using our classes

var mycat = new Cat;
var mykitten = new Kitten;
var mydog = new Dog({
	action: 'woof woof woof'
});


// Now we can call the abstract methods for each of our objects

mycat.talk();
mykitten.talk();
mydog.talk();