There are two differences between define and typedef. Firstly, typedef obeys scoping rules just like variables, whereas define stays valid until the end of the file (or until a matching undef). Secondly, some things can be done with typedef that cannot be done with define. Examples: Code: typedef int* int_p1; int_p1 a, b, c; // a, b, and c are all int pointers. #define int_p2 int* int_p2 a, b, c; // only the first is a pointer! Code: typedef int a10[10]; a10 a, b, c; // create three 10-int arrays Code: typedef int (*func_p) (int); func_p fp // func_p is a pointer to a function that // takes an int and returns an int
