Four Key Concepts of Computer Programming

Last week Rob Miles who is taller than I am, has more hair than I do and has an English accent all of which indicate he is probably a lot smarter than I am left a comment on one of my posts that lists his idea of the four key concepts in programming. He left to comment on Do We Need A New Teaching Programming Language BTW. The post and his full comment are worth the read. Rob’s list was:

  • Process data (assignment)
  • Make decisions (if)
  • Loop (do - while, for)
  • Use indexed storage (arrays)

Among other things he said:

If you can do these four things you can write every program that has ever existed. Sure, the code won't be pretty, but it will solve the problem. In my course we focus on algorithms at the start because this is where we actually create behaviours  [note classy British spelling which adds credibility] that solve problems.

In all seriousness, Rob is a great teacher who also writes some really good textbooks. He really knows his stuff. All of that not withstanding I kept trying to think of a fifth thing to add to his list.

I thought about input/output for a long time. But I/O is such a platform dependent sort of thing. It depends not only on the language but the operating system and even available hardware. Input via a key board is different from punch cards (remember those) and still more different from input via a Kinect sensor (let’s keep in mind that there is a future). As I recall the PASCAL standard did not specify requirements for input/output and left it to the developers for individual platforms. So that probably doesn’t fit.

I thought about variables but that is sort of covered by process data and indexed storage. Even internal data representation which I see as a key computer science concept is probably not as key for programming. I have successfully used programming languages that only stored integers and strings. Well maybe there was a Boolean but I forget. I managed to write some useful applications anyway. Some even dealing with money.

Recursion? How often do you really need recursion? And a lot of things that recursion is used for loops will do just fine for. So while one should learn recursion and a really good programmer should know how, and more importantly when, to use it I don’t think it fits the top four or five list.

Would you add something? Remove something? Overall what do you think of Rob’s list?

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