What Leads to Coding Mistakes?

#discuss

What factors contribute to programmers making frequent mistakes? Are there specific habits or practices that tend to lead to errors in code?

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Top comments (10)

Kaamkiya • Feb 28 • Edited

There are infinite thing that can cause errors, but some of the most common are ...

Not being on the same page as co-workers or other people on your team
Not understanding the codebase
Using C++
Writing unreadable code
Not commenting code
Using nondescript variable names (naming a variable hp instead of heightOfPerson, for example)

... and more.

Bernd Wechner • Feb 29

Tee hee, had to chuckle a little as part of me thinks that one source of errors is in fact the misapplication of ideas, like "infinite" (there most certainly is not an infinite source of errors I can assure you, not even almost).

ProgramCrafter • Feb 28

Let me continue with fairly more complex, but yet not uncommon reasons!

Overcertainty that input will have certain properties (often coupled with not having project structure in mind);
Trying to change existing code to do similar, but another, thing;
Writing functions with large amount of parameters of one type, then accidentally swapping them;
Separating logically connected variables into separate objects, then expecting them to be consistent.

Mohammed • Feb 29 • Edited

Testing (or lack thereof).

It's super important to make sure that your code works for all inputs, valid or invalid (and handles them gracefully). For example, what if the math works out to a division by zero in a certain statement? Or if the file name itself has a '.' in it and now your code thinks the file extension is "InsertFileNameHere"?

AdamDSherman • Feb 29

Tech debt. Out of date code that prevents newer code from being implemented properly
Deadlines
Poor code review or QA practices
Late night and rushed releases
Lack of automated testing and linting applications
Poor documentation and communication between devs
Learning new tech

Mike Stemle • Feb 28 • Edited

Time and staffing constraints are the root of all software quality evil. “Just get this done” is a great ethos for getting something, but it sucks at guaranteeing long-term satisfaction with what you got.

I’ve seen companies refuse to grant more time for testing, and then punish the team for releasing bugs.

It is far too much to ask developers to be perfect. AI won’t be perfect either.

Bernd Wechner • Feb 29

I'm tempted to take a step back and suggest the only real source of errors is human nature. The rest is detail including the details of trying reduce the likelihood and impact of errors and we have many methods for that, with a cost/benefit function that follows the standard Pareto curve (or 80/20 rule). When it's important, like a plane's control system, an x-ray machine, a banks back end) we can produce as good as failure free performance (as the curve is assymptotic and perfection an unattainable myth we can only ever push hard against the limits at great expense).

Where the consequences of errors are low and other features take priority (literally features or time to market for example) errors will be part of the product.