Abstract MooTools Class Basics

Human.js

var Human = new Class({ 
  initialize: function(name, age){
    this.name = name; 
    this.age = age;
  }, 
  isAlive: true, 
  energy: 1, 
  eat: function(){
    this.energy++;
  } 
});

// usage
var bob = new Human('Bob Ross', 50);
bob.energy; // 1, from the prototype
bob.eat(); // assigns bobs own energy to 2
bob.energy; // 2, prototype not checked anymore
bob.name; // Bob Ross, nothing to do with prototype

Ninja.js

var Ninja = new Class({ 
  Extends: Human, 
  Implements: [Warrior], 
  initialize: function(side, name, age){
    this.side = side; 
    this.parent(name, age);
  } 
});

var blackNinja = new Ninja('evil', 'Nin Tendo', 'unknown');
blackNinja.eat(); // inherited from Human
blackNinja.attack(bob); // copied from Warrior
bob.isAlive; // false, bob never had a chance
blackNinja.kills; // 1, from Warrior

Samurai.js

var Samurai = new Class({ 
  Extends: Human, 
  Implements: [Warrior], 
  side: 'good',
  energy: 1000 
});

usage.js

// assuming #jack is an element
// and our samurai class takes
// a jQuery selector for the first
// argument in the initialize method

// instantiate a class instance
$('#jack').samurai(); // new Samurai('#jack')
// call a method
$('#jack').samurai('eat') // jack.eat()
// get a property
$('#jack').samurai('isAlive'); // jack.isAlive
// set a property
$('#jack').samurai('kills', 2); // jack.kills = 2
// chain stuff
$('#jack').samurai('attack', bob).animate().css();

Warrior.js

var Warrior = new Class({ 
  energy: 100, 
  kills: 0, 
  attack: function(target){
    if (target.energy < this.energy){
      target.isAlive = false;
      this.kills++;
    }
    this.energy = this.energy - 5;
  }
});

Nice example!