Is It a Good Idea to Add O Properties on the Original Objects?

I think that adding o properties on the original objects is way, way dangerous and problematic. If you want to know all the lines on which something is an instance of something else, if you just grep for this, you'll get most of your programme. I will say one thing though, sometimes when i see cot that makes extensive use of this, i feel like the itch to fix that code. You should not try to refactor large portions of an application for no good reason. And should generally abide by the existing colding practices within the coat days. The delet operator doesn't do what you think that it does. Don't use var or let. It's a question of taste