Trying to implement a usefull and easy-to-read way for declaring classes in JavaScript.

class.js

/* Simple JavaScript Inheritance
 * First draft!
 * @author Benny Bennet Jürgens (http://ben.nyben.net)
 * CC-by-sa 3.0 - please provide my name and url
 */
;(function() {
    "use strict";
    this.BBClass = function(ctor, proto) {
        ctor.prototype = proto || {};
        ctor.prototype.constructor = ctor;
        ctor.extends = function(parent) {
            function ChildBB() {
                parent.prototype.constructor.apply(this, arguments);
                ctor.apply(this, arguments);
            };
            ChildBB.prototype = ( typeof Object.create !== 'function') ?
                (function(parent) {
                    function F() {};
                    F.prototype = parent.prototype;
                    var prototype = new F();
                    prototype.constructor = ChildBB;
                    return prototype;
                })(parent)
                : Object.create(parent.prototype, { constructor: { value: ChildBB, enumerable: false }});
            return ChildBB;
        }
        return ctor;
    }
}).call(this);

var Person = BBClass(function(isDancing) {
    console.log("person");
    this.dancing = isDancing;
});

Person.prototype.dance = function() {
    return this.dancing;
};

var Ninja = BBClass(function(isDancing) {
    console.log("ninja");
}).extends(Person);

Ninja.prototype.swingSword = function() {
    return true;
};
Ninja.prototype.arraytest = [1,2,3,4];

var p = new Person(true);
var n = new Ninja(false);

Person.prototype.test2 = function() { console.log("test2 bestanden"); };

console.log(n.arraytest);
console.log(p.dance());
console.log(n.dance());
console.log(n.swingSword())
p.test2();
n.test2();
console.log("inherit ok?")
console.log( p instanceof Object);
console.log( p instanceof Person);
console.log( p instanceof Person && p instanceof Object && n instanceof Ninja && n instanceof Person && n instanceof Object);

=> person
=> person
=> ninja
=> [1,2,3,4]
=> true
=> false
=> true
=> test2 bestanden
=> test2 bestanden
=> inherit ok?
=> true
=> true
=> true

Improved performance of object definition and addes mixins (aka jQuery.extend - WIP). Latest performance measures: http://jsperf.com/goog-inherit-vs-simple-inherit/6