There's a gotcha the pattern shown in the gist fixes. You'd do yourself a favor by reading http://bit.ly/1FM2nyb. For good measure, check out http://bit.ly/1KdLXwb as well.

I personally do not like Object.create since I believe the pattern shown above works perfectly and I'm not convinced Object.create() adds anything useful to the mix. Anyways, YMMW.

Note lines #15 and #16:

Scout.prototype = new Girl();
Scout.prototype.constructor = Scout;

If you set the prototype property of a constructor function, it "breaks" the constructor property of its instances (that you'll create in the future). As a reminder, in JavaScript all instances have a constructor property that point to the function that created it. For example:

console.log((5).constructor); // logs [Function: Number]

Now let's say you comment out line #16. Given the example above, it follows that

console.log(sarah.constructor);

will output [Function: Scout]. However, it instead outputs [Function: Girl].

That's because assigning Scout.prototype broke constructor property of its instances. To fix that, we need to remember to always set constructor property as shown in line #16 of the Gist.

In summary the "native pattern" (as in what's followed in creation of JavaScript's native objects) for inheritance in JavaScript requires the following three steps:

1. Remember to call super constructor function from the child constructor function (line #11).
2. Set prototype of child to new instance of super (line #15).
3. Set prototype.constructor of child to child (line #16).

A simple and clean example of this pattern can be seen here: http://bit.ly/1PESNli