What should every programmer know about programming?

Question

Please, stay on technical issues, avoid behavior, cultural, career or political issues.

Answer 1

"Hello world" is not a complete application, as there is no demonstrated / programmatic assertion that the output is in fact "Hello world". Code is not complete until it has been unit tested.

Answer 2

Some of these have been posted already, but here is my list:

• Build to the requirements, don't add things you don't need, especially if you "think" you will. If you need it later, add it then.
• How to use Google search. Don't bother your co-worker, until you've looked.
• Don't be clever.
• It's not done till it's meets ALL the requirements, tested, documented, and checked into SVN.
• Proper coding standards, eg: naming conventions

Answer 3

When you have to distribute an application or put a website into production outside the confines of your company, everything that you thought didn't matter, does.

Answer 4

Documentation is very important. More so if you are building something from scratch. It helps to document your ideas before writing any code.

I learned this the hard way.

Answer 5

Know your OS/Platform before you start coding.

If you code Windows/Linux/Android/iOS etc. start by learning the OS. If you target something else such as Web the same goes there.

Answer 6

My first vote would be for Naming Conventions.

Answer 7

How to do it.

... What do you mean I need 15 characters?

Answer 8

Don't forget about the person who is going to use the software you're creating.

Answer 9

All data has to live somewhere. You can find it if you look hard enough.

Answer 10

Can't comment yet, but on the topic of "Testing and debugging skills", this little gem by Ned Batchelder is a must-read. (Then gain, much of what he has to say on debugging and assertions is worthy of consideration.)

Answer 11

Every programmer should know that the only thing s/he knows is that s/he knows nothing. There is a lot to be learnt.

Answer 12

Know the basic regular expression syntax including conditional grouping. Stay away from using library specific regex command addons or at least comment/factor out those parts.

Answer 13

Regular expressions

I can't say how many times simple regular expressions converted data that people thought would take days to manipulate. It must be present in every programmer toolbox.

Sure, we can't forget xkcd:

Answer 14

Every programmer should know how a processor works.

Answer 15

All problems in computer science can be solved by another level of indirection.

Answer 16

Design your code, and if your manager wants to use a RAD style approach try and get as many details as possible. Then when more functionality is added try and think if the existing code can be rewritten before just piling on more code and you end up with a highrise instead of a house.

Answer 17

Run the code or logic in your head or paper first. Don't rush to hit the compile and run command to test it out.

Answer 18

Recognize that anything that can go wrong will go wrong. Spend very little time writing code – but recognize and reuse common patterns. Refactor code constantly to reach the ideal design.

Answer 19

If something can go wrong , then it will . Assume the worst case

Answer 20

If the system works and you change it and it stops working, the change you made is what broke it, even if that cannot possibly be the case.

Answer 21

They need to know about the power of closures and start using them.

Answer 22

Hexadecimal notation. Also bit fields -- ANDing, ORing (inclusive and exclusive), complementing (1's and 2's), bit shifting.

Answer 23

Program with maintainability in mind.

Answer 24

There are some very good suggestions here, but I'm surprised no one has mentioned the excellent series of articles by Ulrich Drepper: What every programmer should know about memory.

Answer 25

every programmer should have a firm grounding in software engineering, and also system analysis/design and information systems concepts. this way if they are called upon to contribute substantially to systems analysis/design and/or information architecture, they will be in a position of knowledge + opionion..whereas normally it seems to be just personal opinion that usually simply stems from personal preferences instead of best problem solution. software engineering is a bit harder to measure, but the pre-requisite knowledge is available out there, and at suitable university degree courses where they teach more than just how to cobble a bit of code together. anyway this is not meant to be negative because the main spirit is but improvement, but then i've worked with some people who have no IT knowledge whatsoever or there's the single minded "script kiddies" that code and re-code (and only in their language of choice) and only see every problem as a repeat of previously applied solutions (by that coder.) so i would much prefer if programmers concentrated more on the larger picture in terms of software engineering (SSADM) and looked at problems as opportunities to do better for the client.

Answer 26

It stands in a few letters, really:

• RTFM (and for the kewl kidz today: JFGI)
• DRY
• KISS
• H2G2

Ok, I'm over-simplifying, but basically if you are pretty autodidact, never stop to learn, and are a bit of a perfectionist, you should have the basis to become a good programmer.

Anything beyond that would be more specific to particular roles and technologies.

Answer 27

When someone asks you to build something, remember: they are also asking you to maintain it. Possibly, forever.

Answer 28

That whatever programs do, more than telling a machine how to do a work, they are a most unambiguous way of showing fellow human beings how to do a work.

Answer 29

Be Master of Something, but Be Aware of Everything !!!!

Answer 30

Every programmer should bind FindNextSelected and FindPreviousSelected actions (visual studio) to keyboard keys (preferrably F4 and F2). You get two things from that:

1. Faster way to navigate between different points of variable/function/substring usage (faster than with "Find all references")
2. Possibility to diff things inside one document. By jumping back and forward while searching some substring you can see the differences between different locations. No need to use Winmerge when need to compare parts of the same document.