Based on the idea that objects inherit from objects, Douglas Crockford advocates the use of an object() function that accepts an object and returns a new one that has the parent as a prototype:

    function object(o) { 
    function F() {} 
    F.prototype = o; 
    return new F(); 
    } 

If you need access to an uber property, you can modify the object() function as follows:

    function object(o) { 
    var n; 
    function F() {} 
    F.prototype = o; 
    n = new F(); 
    n.uber = o; 
    return n; 
    } 

Using this function is the same as using extendCopy(), you take an object such as twoDee, create a new object from it, and then proceed to augmenting the new object:

    var triangle = object(twoDee); 
    triangle.name = 'Triangle'; 
    triangle.getArea = function () { 
    return this.side * this.height / 2; 
    }; 

The new triangle still behaves the same way:

    >triangle.toString(); 
    "Shape, 2D shape, Triangle" 

This pattern is also referred to as prototypal inheritance, because you use a parent object as the prototype of a child object. It's also adopted and built upon in ES5 and called Object.create(). Here is an example:

    >var square = Object.create(triangle);