Techniques to Employ
for Good Design

Keep main( ) small and readable by writing functions that are either modules or are for hiding details.
main() should be a skeleton of the program
Write modules whenever possible.
- Do not allow functions that are modules to be dependent upon #defines. Pass values to these functions rather than using symbolic constant names within the function's code. This makes a function more general and promotes reuse.
- See the changes made to GetRandomNumber( ) as an example.
- Lecture 4's GetRandomNumber( ) relies upon #defines. (BAD!!!)
- GetRandomNumber() in the Cards example below has the necessary values passed in as arguments and is now independent code (GOOD), which is essential for it to be a module.
Remove any large section of code that accomplishes one purpose from main() and place it in an appropriately-named function for hiding details.
Replace any numbers (constants) that "magically appear" in main( ) and in any "hiding-details" functions with symbolic constants (meaningfully named #defines) for readability.
- " magic number" is the disparaging phrase used by computer programmers for "a special constant used for some specific purpose". It's magic because its value or presence is inexplicable without some additional knowledge.