Q: What's the difference between
const MAXSIZE = 100;
and
#define MAXSIZE 100
A: A preprocessor #define gives you a true compile-time constant. In C, const gives you a run-time object which you're not supposed to try to modify; ``const'' really means ``readonly''. See also the question 11.8. (But in C++, const is closer to #define.)
Additional links: longer explanation