Common Programming Mistakes and the Lessons They Teach

As programmers we all start as beginners and inevitably make mistakes; reflecting on these errors helps us grow.

Local file include error: Using include "d:\xxxxxxxxxxx.h" caused runtime failures when the code was shared, illustrating the importance of portable file paths.

Obscure character usage: A rare Chinese character "丨" was used as a string separator, confusing collaborators and leading to debugging headaches.

"If‑else" explosion: Writing dozens of nested if‑else statements reduces performance and readability; the article advises switching to a table‑driven (lookup) approach.

Meaningless variable names: Declaring many variables like int x,y,z,w,v,u,l,m,n,o,p,q,r,s,a1,b1; makes the code incomprehensible even to its author after a short time.

Hard‑coded output: Instead of calculating results, some developers directly output fixed values, which can lead to security issues when used for passwords or other sensitive data.

Thread waiting misuse: Using QThread::sleep(1000) actually sleeps for 1000 seconds, demonstrating the need to understand API units (seconds vs. milliseconds).

Missing return statement: Forgetting to return a value from a function caused unexpected null results in the calling code, a reminder to always include proper returns.

The article concludes that acknowledging and learning from these “stupid” mistakes fosters humility, continuous learning, and better coding practices.