Sunday, December 4, 2011

What is programming?

What is programming? I get that question a lot from my non-programmer friends. The interesting thing is, I had never really asked myself that question - and if my Google-fu hasn't failed me, no-one else has really answered this question, either (at least in a way a beginning programmer or non-technical person can understand ). So I'll do my best to do answer that now, and I'll voice my thoughts about the answer a little too :)

First off, what are programmers trying to accomplish when they write a program?  They're trying to solve some problem. Even when you're writing a small one-page script for fun, you've set some problem up for yourself to solve. For example, I wrote an RSS reader in Python a while ago, that notified me of new news items via libnotify - a program/framework that lets you make pop-up alerts on Linux.

Even with such a small utility (it was under 300 lines of code, if I recall correctly), there was a problem for it to solve: Check a list of site's RSS feeds every so often, and if there are any new items, set up a libnotify alert. Yes, it's a small problem, but it is a problem to solve nonetheless.

So, now we know what programmers are trying to accomplish when they write a program, how do they write the program itself? This is another question I get often - how in the world do you write a program?

Well, now the programmer knows the problem he/she is trying to solve, the programmer must now come up with a solution to that problem. Going back to my RSS reader example, my solution was for my reader script to be called via cron (a UNIX/Linux program that runs other programs every so often), and save the etag (basically a hash of a RSS feed's contents) of each feed, and check them against the current etag of the feed we're trying to update. If the etags are different, that means there is new content, so fetch the new content and make a libnotify alert.

Note that the solution to our problem is not code, and it's not UML or anything. It's just a simple, step-by-step, human-readable solution. That's how solutions to the problems your program is trying to solve should be - simple sentences, nothing more. UML and code snippets are useful, but if your solution cannot be explained in plain English (or your native language, if that's not English), you most certainly will not be able to implement it in code. I like the way the Zen of Python puts it:

If the implementation is hard to explain, it's a bad idea.
If the implementation is easy to explain, it may be a good idea.

So, now we know what we're trying to solve, and how we're going to solve it, we have to convey our solution to the computer in a way it can understand and run - in other words, actually implement our solution in some programming language. This is the most complicated part of programming, and the most error-prone - most software bugs are created during this step, so programmers must use extra caution while performing this task.

Unfortunately, Murphy's Law often hits hard during this step.

No matter how careful you are while actually writing your solution in some programming language, you will make mistakes. When this happens, you'll have to find where the bug occurs, figure out why the bug occurs in the first place, and then devise a way to fix the bug. Again, going back to our RSS reader example, I made a mistake that caused the RSS reader to make a pop-up notification for every news item, even for old items. My solution was fine, but I made an error implementing my solution, so I had to fix it.

Now we've answered the question of what programmers are trying to accomplish when they write a program, and then how they convey that solution to the computer in a way it can understand, we can answer our original question: What is programming?

It is the act of finding a solution for a problem, and then implementing that solution in a way a computer can understand - nothing more, nothing less. Whenever you sit down to write code, you're trying to solve some problem. This is practically identical to what mechanical and electrical engineers do for a living, which is quite interesting: Are programmers "software engineers"? Should they treat every line of code they write with the same amount of professionalism and excellence a mechanical engineer treats the design of a suspension bridge he's made that some construction workers are going to build? Those questions have been the subject of much debate in the software industry for more than a decade.

If you're not a programmer, now you see there's no "black magic" in programming. All that a programmer does while he programs is solve problems. Who knows, now you know programming isn't as complicated as most non-programmers make it out to be (it's still not a breeze by any means :)), you just might want to try programming out for yourself. :)

If you're a programmer, the next time you sit down to write some code, think about the answers to the above questions, and remember what you're doing when you're writing code - you're solving a problem. You just might be surprised how much more carefully you write code. :)

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