Programming Mistakes To Avoid

snydeq writes "InfoWorld's Peter Wayner outlines some of the most common programming mistakes and how to avoid them. 'Certain programming practices send the majority of developers reaching for their hair upon opening a file that has been exhibiting too much "character." Spend some time in a bar near any tech company, and you'll hear the howls: Why did the programmer use that antiquated structure? Where was the mechanism for defending against attacks from the Web? Wasn't any thought given to what a noob would do with the program?' Wayner writes. From playing it fast and loose, to delegating too much to frameworks, to relying too heavily on magic boxes, to overdetermining the user experience — each programming pitfall is accompanied by its opposing pair, lending further proof that 'programming may in fact be transforming into an art, one that requires a skilled hand and a creative mind to achieve a happy medium between problematic extremes.'" What common mistakes do you frequently have to deal with?

Maintaining code by others are always a nightmare

[TheViciousOverWind]

Until you spend enough time with it, to learn why the original programmer did as he did.

As I see it, most projects start out with a good structure and the best of intentions, and then comes deadlines and the developer having to juggle several projects at once, and then a shortcut is taken here, then there. And suddenly you end up with a non-documented project where the only person that knows how it works is the original developer.

There will however always be BAD code by bad programmers. I've taken over Java progress where everything was OOP'ed into hell (as in a bazillion classes more than was needed for the application) and PHP projects which should be OOP'ed but consisted of about 500 files that included each other in a huge confusing net.
I've also had to take over projects where the original developer was using new technology because he thought it would be fun (at the expense of the customer). Having a huge website in PHP/MySQL and then having crucial parts of it in Ruby/PostreSQL is just a maintenance nightmare.