Naming Things Well - Best Practices Series

Some BASIC programmers come from the experience of needing to fit their programs in 4K of RAM or less, so it feels natural to give variable names single letters such as a, b, c or I, j, k. Of course most classic BASIC interpreters don't have support more for than 2 characters for variables. Some BASICs will let you call your variable 'count' but only the c and o will be recognized as the variable name.

To be fair, I've seen more than a few C programmers also choose single character variable names. Bad habits are language agnostic. ;)

In programming languages today including Liberty BASIC, you can give your variable names and other things such as subroutines and functions longer names. What's more, computers have so much memory that we can dispense with trying to save memory with short variable names. And if you're used to using line numbers I strongly encourage you to discard them in favor of named labels. Once you are used to this it will make your programming better.

Why does it matter?

Programming is an exercise in thinking and so it is really important to pick the best possible names for the parts of your programming ideas. When you or somebody else reads your code it will help to understand the code if the variables and function/sub names are chosen well.

What if you are about to go to the store to buy some milk and you told your friend "I'm g to the s to b some m." How well would you be understood?

So, when you write code ask yourself (or the coder next to you) what is the best name for this variable or routine? Later on you may even realize there is a better name and so don't hesitate to act on that impulse and update your code with the new better name.

Think of your coding as a journey to discover the truth of the code, and naming things is an important part of the discovery.

Raspberry Pi Deluxe Starter Kit Giveaway!

We are giving away a deluxe Raspberry Pi kit, and this includes all kinds of nice accessories including an electronics learning lab.  No purchase is required, so enter by Aug 31, 2017 to be included in the raffle.

Check out the video here for details about the kit!  https://youtu.be/toln-Z_z4RY

To enter the drawing, send an email to carlg@justbasic.com with the subject Raspberry Pi Contest, and we will send you a confirmation email. The winner will be announced at the end of August 2017.

Please share this information with your friends.

Blast from the past - Whatever happened to PEEK and POKE?

I am reposting the following blog entry from ten years ago because it has been one of the most popular posts ever according to Blogger's statistics graph.  The link at the end of the post was broken, so I updated it.

Enjoy!

Sometimes I'm asked how to PEEK and POKE using Liberty BASIC. The short answer to this is, you can't. The long answer is more complicated.

The original home computers (like the classic Commodore 64, TRS-80, and Apple II models) were designed to be completely open to their owners. Most of the different parts of the computer like the sound, graphics, keyboard and joystick (there were no mice back then) were controlled by mapping them to different memory locations. So, the built-in commands didn't do everything you need? It was common to control the computer's equipment directly by sticking values into the memory locations that control that equipment, and reading the status back out. This was done with POKE and PEEK. This was a lot of fun, and usually useful too.

Since these early machines didn't multitask it was pretty safe to steal control of things away from the BASIC interpreter (which was a much operating system as there was). Then computers started running Windows, the Mac OS, Linux, etc. and allowed more than one program to run at a time. PEEK and POKE became problematic because if one program decided to mess with the screen for example, it might interfere with what other programs need to do their thing. Not only that, but computers today all have different kinds of hardware in them, so even if you could PEEK and POKE the exact memory locations would be different from machine to machine. So that's the bad news. :-(

The good news is that we can still have a power trip. How? Your operating system manages all the hardware for you behind operating system functions. These functions make every computer look more or less the same to the programmer. You can use these functions to do a lot of powerful things and most languages have a way to use them. For example Liberty BASIC programmers can use the CALLDLL command to make Windows API calls, which are the operating system calls of the Windows operating system. These are more complicated in general (and you can fill a whole bookshelf with information about them) than the old fashioned PEEK and POKE, but at least we aren't left without some way to pull rank on our computers. ;-)

So if you're missing the power and coolness of PEEK and POKE, why not try your hand at API calls?

Here is a useful link to get you started:

http://www.libertybasicuniversity.com/lbnews/nl108/index.htm

Commodore 64 Twenty-fifth Anniversary

Here is a YouTube video of a 90 minute presentation celebrating the 25th anniversary of the Commodore 64 home computer. The C64 was a groundbreaking machine and I know I'm not the only one who learned a lot from this wonderful machine and similar ones like the TRS-80, the Apple II, the Atari 800, and the TI-99/4. I programmed Commodore computers in BASIC, 6502 assembly language and Forth. Great stuff.

Go check this out for a fun romp into the past. The presentation touches on much more than just the C64. http://video.google.com/videoplay?docid=3754836267385299753