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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?
And now for the printable version with all the tips on one page:
http://infoworld.com/print/145292
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What common mistakes do you frequently have to deal with?
- Software only tested by programmer.
- Manual only written by programmer.
- Support can't do a day without programmer.
A good programmer should know when to delegate. Or their boss should. Depends on office culture perhaps.
Hivemind harvest in progress..
...just try to avoid errors and you should be set.
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.
My <1000 UID is with a hot chick
The most common programming mistake to avoid: Reading badly written articles about "what programming mistakes to avoid".
Doesn't mistake number 2 contradict number 1? Or am I missing something?
Yup. FTA:
Below you will find the most common programming pitfalls, each of which is accompanied by its opposing pair, lending further proof that programming may in fact be transforming into an art -- ...
Hivemind harvest in progress..
I very rarely see programming mistakes. There seems to be 2 kinds of programmers.
- Those who care about what they do and try hard.
- Those who don't care about what they do and don't try hard
The later write terrible code, but it is just because they are either lazy or aren't suited to the profession and can't get enthused. Very rarely do you see someone who cares about there work make a big mistake (and if so they are probably just starting out).
Doesn't mistake number 2 contradict number 1? Or am I missing something?
The whole lot is full of contradictions:
4: Delegating too much to frameworks 8: Reinventing the wheel
9: Opening up too much to the user 10: Overdetermining the user experience
5: Trusting the client 6: Not trusting the client enough
I think that there is a meta-message, akin to Buddha's middle way. Don't take any rule to extremes.
Fair enough. So debug while you code. Seems like good advice.
s/debug/test/
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Programming mistake #0: Believing that your computer degree (Computer Engineering or Computer Science alike) automatically puts your code in a high level of quality.
Not to bring any academia vs industry argument, but many students miss the idea of a Computer degree with programming courses in it: The degree intentionally doesn't go to details because it needs to give you a background into a broader set of subjects. Industry needs one to be very attentive to details in that one thing he's doing at the moment.
The only common mistake I see is not firing the programmer who makes any of those "common" mistakes. There is absolutely no reason for any of this shit to be "common" unless "programmers" who make them are uneducated dumbasses who should never be allowed anywhere near software development.
Now, please, give me the list of "common mistakes" made by surgeons and aircraft engineers, and compare them with this list of amateurish crap.
Contrary to the popular belief, there indeed is no God.
Pointer typedefs were a bad idea in the 1980s. They're just terrible today. One pet peeve of mine is this:
typedef struct _FOO { int Blah; } FOO, *PFOO;
void
SomeFunction(const PFOO);
That const doesn't do what you think it does. There was never a good reason to use pointer typedefs. There is certainly no good reason to do so today. Just say no. If your coding convention disagrees, damn the coding convention.
1) VB
2) Perl
3) Silver bullets
3) Writing your own "framework".
4) Using somebody else's "framework".
No folly is more costly than the folly of intolerant idealism. - Winston Churchill
Is it indecent of me to reminisce on the days of olde when such a topic would simply turn into a lengthy discussion mocking BASIC programmers?
Violence is the last refuge of the incompetent. Polar Scope Align for iOS
#1 - If you are a programmer, BE A PROGRAMMER and manage the pointers and memory allocations yourself. Garbage collection is for little boys. Men deal with it on their own with techniques that work and are efficient.
So mega-strongly disagree dude. Not saying you shouldn't do heavy lifting when necessary -- just that you should only do it when necessary. Don't re-invent the wheel every time. Frameworks exist that do work for you for a reason. Chose your frameworks well, understand them in depth, and you can do good things. If you "start from the first principles" every time, you end up with a humongous fucking surface of new code -- which is bound to have a nasty bug or three. It comes down to choosing the best tools for the job.
#2 - Initialize all variables to known values. int i; doesn't cut it. int i=0; does.
True dat. Lots security pitfalls here too -- not just garden variety bugs.
#3 - Use descriptive variable names
So true. Corollary to that: because a variable name is descriptive, don't make wanton assumptions about it.
#4 - you shouldn't be allowed to program anything new until you've been a maintenance programmer for a few years and seen the crap code that others puke into the world. Your crap code stinks too, BTW.
I'd modify this to say "always, always, always have a peer-review process". Junior devs are prevented from checking in crap because it gets caught by senior devs. The junior devs also learn quality habits from reviewing senior devs' code. Multiple reviewers is always a good thing. Review your design among the entire team before anyone writes a single line of code. Remember to keep security in mind when reviewing code. Use static analyzers when you're done with the "human" aspect of the review. Apply every imaginable quality bar to your code, and only check it in once it has passed scrutiny.
I've not worked as a programmer for, hmm, maybe 15 years and all of this was known way back even before I "retired" from that line of work. Perhaps all these levels of abstraction upon abstraction make things harder to understand. Back in my days these "pitfalls" were obvious because we all (well, not all, but a lot) knew ASM and actually even used it regularly (even inline, *shudder*).
Someone above mentioned pointer typedefs and gave the example of typedef struct { int Blah; } FOO, *PFOO; (yes I left off the bit before the the opening brace deliberately.) and then suggesting that people don't know that void SomeFunction (const PFOO) {} doesn't behave as expected. Now this could, I suppose, be seen as a failure of the language. But, shit, any idiot who understands the underlying logic can see why that causes problems. Which goes back to my point of maybe all these modern levels of abstraction and getting away from the machine are, in some ways, detrimental.
Now, get off my lawn. Umm, except I don't have a lawn because I sprayed the growth inducing hormone RoundUp all over it, but that is beside the point. I think.
All true. My personal favorites are larger, long running projects where all of the above is true and all kinds of undocumented business logic is embedded in the code making a rewrite unfeasable and you have to decide which part of the code is outright sloppy or bad, which parts are feasable and which parts aren't actually being used anymore. Top that off with the original developers being unavailable (either dead or fleeing) and you'd be painting a pretty accurate run-of-the-mill software enviroment.
---
"The chances of a demonic possession spreading are remote -- relax."
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 see this one as a lack-of-experience problem. People have good intentions and want to build scalable, extensible, maintainable code. This is good. Unfortunately however, they're wrong. The apps they're building are small irregardless of the amount of thought they put into them, and they won't have to scale and extend the way they think they might - you don't need interfaces and impls and arbitrary inheritance for everything when the webapp is 4 screens of Spring WebFlow! Sure, if you're building something that warrants it, this is the way to go, but most of aren't building apps that big or flexible. It seems to take time to learn this, and to know when to apply the patterns and when to just build it.
As a smarter man than I once said, Make things as simple as possible, but no simpler. If you do that, your code will work, it'll be understandable by the next guy, and you'll have a fighting chance of meeting your deadlines.
Forget thrust, drag, lift and weight. Airplanes fly because of money.
Yes it does. The difficult part is knowing the balance, as indicated by the summary: "programming may in fact be transforming into an art, one that requires a skilled hand and a creative mind [...]"
Personally, I believe we'd be better off it professional programming transformed from an art into an engineering discipline. IMHO, building robust and efficient applications should be a boring and repetitive exercise in design and implementation of prescribed design patterns... maybe then we'd turn our industry's abysmal success rates around.
Forget thrust, drag, lift and weight. Airplanes fly because of money.
My two most common mistakes:
Crumb's Corollary: Never bring a knife to a bun fight.
Allowing too many options / features in the design. The classic example being unable to decide whether feature A or B is best, and ducking the issue by including them both
Assuming 5 working-days of effort can be achieved in a working week. Conveniently forgetting about all the office overheads such as "progress" meetings, timesheet administration, interrupted work, all the other concurrent projects. Even the most efficient, single-threaded operation needs half a working-day per week just for the trivia.
Following on from that, conveniently forgetting about annual leave commitments, national holidays and the possibility of sickness. If 5 working-days per week is impractical, 12 working-months in a year is downright negligent.
The tacit assumption that testing will inevitably be followed by reelase - rather than bug-fixing.
Holding the end-date constant while delaying the start, or presuming that all delays in the specification, design, approval stages can somehow be reclaimed during coding (how: by thining faster?)
politicians are like babies' nappies: they should both be changed regularly and for the same reasons
The biggest programming mistakes I've had the displeasure of making, or discovering in others code, almost always centre around one of these two problems:
1. The code is over-engineered
2. The code was abstracted before there was even a need for the abstraction.
I remember when I was less experienced, how thrilled I'd be over code that was clever, solved many problems aside from the one I was trying to solve, and had some clear reusability built in. What a work of art, I thought.... until I eventually realised that much of the extra code I had written didn't get used, the abstracted code was never reused - or even if it was, I couldn't predict how it would be reused and the abstraction was clumsy at best, useless at worst.
It's sad when this happens - good intentions, but the end result is a lot of waste. I'm embarrassed to look over my earlier code which is like this.. I like to think I do it less now, but the temptation is always there... I'm going to need to do this later anyway... I can just abstract this bit here and reuse it some day in the future...
My advice now... Don't do it! Just wait until the reuse case comes along, or the new feature request comes along, and *then* do it. You'll know so much more about the problem domain then, or you might avoid days (weeks!) of wasted effort.
"The whole lot is full of contradictions"
No, it isn't. It goes "don't do that... but don't fall in the other extreme".
That's on line with his central idea that programming is "an art, one that requires a skilled hand and a creative mind to achieve a happy medium between problematic extremes".
That, and being able to figure out what people actually want in the first place.
Quite a few projects fail simply because the people requesting it have no idea what they actually want. They can't articulate their needs, or why they need it, or even where the idea came from. If you can't nail that down, the rest of it is a crapshoot.
(The only thing worse is when they DO know what they want, and it's for entirely irrational reasons.
"We want Sharepoint!"
"Okay, why?"
"Umm... because we do!"
"What does Sharepoint do that you want?"
"Documents, and stuff!"
"Sigh...")
-- "So they told me that using the download page to download something was not something they anticipated." - Bill Gates
Don't get me started on preventing programming mistakes. If I'd address the most common programming mistakes that I've ran into in the wild and write an article about each of those mistakes at a time, I would end up with a whole book on the matter and would probably call it "Growing Better Software".
I find the given top 12 list of mistakes a bit weak- I'd be able to avoid all of these and yet write horrible code. My personal recommendation for a top 12 of programming mistakes to avoid would be:
1. Failing to check function parameters before using them: null pointers, limits, lengths, etc. This will make your program unstable and/or unpredictable.
2. Spending too little time thinking about and designing the data structure of the application. This will make you get stuck when maintaining/extending your application.
3. Following every market hype - When the marketing bubble bursts, you'll have to start over again.
4. Designing user interfaces without actually involving users - You'll be surprised how easy it is to confuse users.
5. Infinitely deeply nested if/else statements - This will make code absolutely unreadable.
6. No documentation whatsoever - Who's going to maintain your code after you change jobs?
7. Ignoring existing, universally accepted standards - so you'll cause interoperability issues or be doomed to either reinvent the wheel.
8. Hard-coded values/magic numbers - as a result, any change must be made in code rather than allowing power users to configure their own system.
9. Littering code with global variables - this implies statefulness of code, making it pretty near impossible to predict how a function will behave next time it is called.
10. Being unaware of the "Big O" order of your algorithms, causing code to be unnecessarily inefficient.
11. Strong platform dependency: This can shorten the lifetime of your application to whenever the next platform upgrade takes place, or keep you stuck at the current version of the current platform forever.
12. Thinking you can figure out everything by yourself - In learning by doing, experience can only follow from making mistakes. By getting yourself a mentor or an education, you can actually learn from the mistakes that thousands have made before you.
13. Stopping at 12.
Visit http://ringbreak.dnd.utwente.nl/~mrjb/growingbettersoftware to download your free copy of the book
Don't take any rule to extremes.
Except sometimes you should. ;)
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.
Taking over projects fitting those descriptions is never a good idea. They are nothing but pain, it's impossible to resolve the problems with the app and the code unless you opt for a complete rewrite. If, however, you go that route the remaining developers will be pissed off because they wrote the crappy code and you are basically saying that their ugly baby is ... well ... UGLY! What's worse, you are saying it out loud for everybody including the PHBs to hear. Eventually you end up being frustrated, your PHB either caves in to complaints about you and puts you in your place or you get laid off. Unless, of course, you anticipate this and quit before he gets the chance. There is no substitute for writing code properly and designing and planning your application properly no matter how insignificant the application seems to be because you will never know which piece of shit app will take off and scale into something much, much bigger. Myself, I learned this from a friendly lecture I was given by my boss after I handed in my first project on my very first job. He made me rewrite the thing entirely claiming it was better that I learned the value of things like database abstraction and MVC separation right away. He was right.
Only to idiots, are orders laws.
-- Henning von Tresckow
Or when BAD programmers, think they are good, and label other programmers as BAD. Which one are you?
Politics is the art of looking for trouble, finding it everywhere, diagnosing it incorrectly and applying the wrong fix.
#1 - If you are a programmer, BE A PROGRAMMER and manage the pointers and memory allocations yourself.
And output formatting. printf is for wussies. Also, networking; if you can't whip up your own application-tailored TCP stack, then you should go back to playing with VB. And GUI toolkits? TOOLKITS?!? What are you doing, building a footstool? Hell, no! Manly programmers don't use toolkits, they use the library of macros they built while apprenticing to Knuth.
You're completely right. All this mamby-pamby resource management crap is for Kindergartners and Excel users. Real Programmers flip bits with soldering irons, and we like it this way.
Dewey, what part of this looks like authorities should be involved?
What are the mistakes I should not avoid?
When we migrated to C++ a while back, my biggest gripe became the number of projects, library, et.al. that weren't documented. I won't name the very popular library, but when I contacted the developers (I was still new with C++ at the time), they told me to "read the headers." Your code is not documentation, no matter how well you comment your functions. There's a subculture out there that I don't get that has the mindset that "it was hard to write, it should be hard to use" (and that's almost a direct quote from a library author). I don't know if it's job security, elitism, nepotism, or what. But, with some projects there's a cold disregard (borderline hostility) towards the people who will actually be using the product.
I swear to God...I swear to God! That is NOT how you treat your human!
I think you overestimate the predictability of the engineering disciplines.