Even as a template I would never use a 2009 resource (updated in 2012) in 2022. I'm sure everything in this resource works fine, it's just probably not up to quality standards in many places which is why the variables have awful names.
This tutorial on Dynamic Indexing has aged very well and I would recommend it. In general, you will benefit yourself by learning the general principles and then building your own loops for a given application. I say this for two reasons:
- The way you format your code/loops, how you group things, variable naming conventions, etc. are all choices on your behalf. You may have a particular way of organizing DI loops that makes sense to you but isn't the way other people format them. Make enough of these sorts of things and you'll discover your own fallback practices and habits that you should just stick to rather than trying to interpret/use someone else's code formatting paradigm.
- There are a variety of different ways these loops may be used and how you may loop 'over' the data depending on what you're trying to do, what objects are involved, and other factors that may constrain the appropriate solution. Instead of being glued to a particular template version of such loops, you'll learn more and write better code by building a few from scratch for different applications. You'll remember doing it a particular way before when you do a similar one again. The specific method used is dependent on the application so you should learn to build a solution for a particular application; the experience only comes from doing it multiple times!