It’s the example of recursion most often used, but it’s not the best example. Of course, to illustrate a better example you need to approach concepts such as fractals and graphical programming doodads. My favorite form of recursion is traversing a directory tree. Regardless, the code for a factorial recursion remains the go-to workhorse.
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An Example of Recursion
A recursive function calls itself. That’s a strange and beautiful concept, one that saves a lot of coding time, but how does it really work?
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Introduction to Recursion
It’s truly a scary thing: A function calls itself. This trick can be done without damage to the space-time continuum, and nothing explodes when it’s done correctly.
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From Text to Integer – Solution
This month’s Exercise is to code a function that converts a string of text numbers into an integer value. If you used the skeleton provided, then your program’s output would look like this:
The string 24680 represents value 24680.Functions in Functions!
For an argument, functions in the C language can take literal values, equations, the result from another function, or any combination of these items. It’s a feature that’s both flexible and confusing.
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From Text to Integer
A program prompts for a value. The user types “12345” at the keyboard, but that input is a string and not the value 12,345. Therefore, the code must convert the string into a value. This task can be accomplished in a number of ways.
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How a for Loop Works
I received an interesting question the other day. A student asked me to explain a for loop. Dutifully, I set out and gave my description, which he found entirely baffling. So I backed up again and gave this explanation:
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ASCII Programming Tricks, Round II
You probably don’t even think about it. How do the toupper() and tolower() functions do their magic? Both functions take a letter of one case and convert it to the same letter of the opposite case. They don’t touch any other characters or symbols.
Well, how would you code it?
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ASCII Programming Tricks, Round I
The clever organization of ASCII character codes lends itself to some useful programming tricks. One of those tricks involves converting from character codes ‘0’ through ‘9’ to integer values zero through nine.
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ASCII Character Codes
ASCII refers to character codes from zero through 127. These codes are interpreted identically on all modern computers. They represent basic alphabetic, numeric, and symbol characters.
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