Whats the difference between using a typedef or a #define for a user-defined type?
See question 1.13. comp.lang.c FAQ list · Question 10.5b 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 comp.lang.c FAQ list · Question 10.6 Q: I’m splitting up a program into multiple source files for the first time, and I’m wondering what to put in .c files and what to put in .h files. (What does “.h” mean, anyway?) A: As a general rule, you should put these things in header (.h) files: macro definitions (preprocessor #defines) structure, union, and enumeration declarations typedef declarations external function declarations (see also question 1.11) global variable declarations It’s especially important to put a declaration or definition in a header file when it
