The Mistakes I made (and Headaches I Caused Myself) when Writing My First Real App

I have learned a lot in my three months of earnest web-development study, so I figured now is the perfect time to reflect on the project that kickstarted my journey, and all of the lousy code that held it together.

I was asked to find a way to track all of the roles, competencies, and skills that my division in my institution would ever need to teach other divisions.

Now, I did not consider myself a programmer when I started the project. My materials were meager: I had a pen, some paper, Excel and an internet connection (maybe not so meager given that last one). Every test that passed and every variable that Debug.print-ed correctly was a miracle to me.

A week after starting, I turned in a hot mess of 1000 lines of VBA code and eight userforms built on top of two Excel worksheets.

Looking back, I made a lot of mistakes.

Here are four of them.

1. I relied on barely-descriptive variable and function names.

This first mistake stepped on my toes constantly. Oh, I want to iterate over the array of skills I just entered? Would that be arr, skills_arr, or newSKills_arr? My functions were worse, with names like arrayCheck -- a datatype and a terrible, no-good, non-descriptive verb.

My program was short enough for this to be a nuisance at worst, and thankfully I am the only person who will ever read the code. But add a few hundred lines and give it to someone else, and I bet they'd be pulling their hair out in minutes.

I give this three headaches out of five.

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2. I repeated myself and my code many times.

Why waste all that time writing a function whose name I won't remember when I can just copy-and-paste the code I need down here?

Again, a big, annoying mistake that was only mitigated by my scale.

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3. No comments, no documentation.

Remember above, when I said:

...and thankfully I am the only person who will ever read the code.

That was a bit misleading because I will never read this code again. And if I do, I wouldn't know where to start. The only comment I made was to attribute a quicksort algorithm I got from StackOverflow. The code is unclear enough, and the lack of comments makes it nearly impossible to figure out.

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4. Too much code lived in the global scope.

This one was due to deficient knowledge of VBA and, unlike the other mistakes on this list, I tried my best to deal with this while I was working on the code.

The only way I was able to regularly and successfully pass data between my forms was to stick a variable in the global scope for all to see. There's probably a way around this, but I was having trouble getting other solutions to work.

Now, I hope it's clear what kind of mess I got myself into:

1. I move a lot of code to the global scope to make it accessible by different forms.
2. My terrible naming conventions meant that a lot of variables, previously tucked away, were now colliding, and I was calling different things by the same name.
3. The lack of comments (and generally poor style) meant that figuring out where these variables were called and what I was doing to them was more work than it should have been.
4. Repeat the above process about 100 times, because I couldn't be bothered to keep my code DRY in the first place.

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And that leads me to the biggest lesson I learned:

For developers, code usability is just as important as application usability.

Small mistakes, minor annoyances, and careless style will pile up.

My constant refrain has been "it could have been worse -- at least my code was short and I was working alone", but the reality is that if I want to do this professionally, these things won't fly.

My scale was small and I was alone. Dealing with these mistakes still took up 15 or 20% of my time. With 10 or 20 more developers and 100x to 500x more code, I would find these mistakes unacceptable.

But this was an important lesson to learn, and I'm glad I got it out of the way so quickly.

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I know my mistakes and lessons probably aren't news to most people reading this, but thanks for reading this far anyway! Next time, I want to dive into a UX problem I created for myself -- one that I spent way to much time on, only to end up with something I hated using.