Sure, however the first part of my comment is not intended to address the essence of their comment, so it has no bearing. What they said is incorrect, and in fact a common mistake and I wanted to correct it.
However, I'd also note that what sktrdie is describing is an Array (in Javascript an Array is just an object with numbers for property names and some helper methods).
As far as I can see there is absolutely zero benefit (and many drawbacks) in using the technique outline in the OP article as opposed to just using an Array.
You could get the same result by simply using an Array directly...or if you want to get fancy, add a few simple helper methods.
In this way (and perhaps others) the article is "bad" and "wrong".