JavaScript Classes

I understand basic JavaScript pseudo-classes:

function Foo(bar) {
    this._bar = bar;
}

Foo.prototype.getBar = function() {
    return this._bar;
};

var foo = new Foo('bar');
alert(foo.getBar()); // 'bar'
alert(foo._bar); // 'bar'

I also understand the module pattern, which can emulate encapsulation:

var Foo = (function() {
    var _bar;

    return {
        getBar: function() {
            return _bar;
        },
        setBar: function(bar) {
            _bar = bar;
        }
    };
})();

Foo.setBar('bar');
alert(Foo.getBar()); // 'bar'
alert(Foo._bar); // undefined

But there are un-OOP-like properties to both of these patterns. The former does not provide encapsulation. The latter does not provide instantiation. Both patterns can be modified to support pseudo-inheritance.

What I'd like to know is if there is any pattern that allows:

• Inheritance
• Encapsulation (support for "private" properties/methods)
• Instantiation (can have multiple instances of the "class", each with its own state)