How did you develop the ability to understand other people's code?

Question

PHP

I am an intern at a web studio, I recently came, I am engaged in an online store, which is written on the CMS opencart (and to be precise - ocStore), before the maximum that the admin did on this CMS, well, maybe I screwed modules and layout, here you need to add functionality or expand already default modules, and here problems begin when a bunch of unfamiliar methods in the controller (it's good that the MVC concept is implemented), models that return a huge amount of data, and then transfer everything to the same ones in the controller, and then it's all rendered into a view. All tasks are done in intensive mode, as if the deadline was yesterday, although today's task, if you understand what I mean.
So it’s interesting to know how each of you developed this skill, because at this stage I realized that I don’t read program code well, and because of this I do a lot of unnecessary manipulations and create crutches - bicycles that are not needed in everything, because everything invented before us.
So advise something junior. Thanks in advance!

Answer 1

I'm too lazy to read all this text, I'll answer the question in the title - I DISASSEMBLED ANOTHER CODE

Answer 2

First, go through GRASP patterns, then GoF patterns. If before you wrote this on another junior using the copy-past method, then this will help you a lot. A good course on patterns is here .
In general, you can learn to ride a bike only by riding a bike ... Practice more and you will be happy. :-)

Answer 3

Only practice will help here, in two directions - this is the study of "best practices", in order to learn how to answer the question "Is this code good, or is it immediately in the trash along with the author?" On this occasion, thematic posts on Habrahabr and thoughtful reading of the comments under them help a lot, but at the same time, you need to form an opinion about the commentators by looking at their posts and ratings - it happens that someone is swearing at 100 floors, but he writes things in general -something correct, that's just the form of presentation he has ahem ... peculiar.
And the second direction is to read someone else's code. It's good if the author of this code is available. Then you can ask him in any form about each comma.