Enumerating Symbolic Constants

For giving symbolic names to numbers, you can use enum instead of #define; it even does type checking!

#define START 1

#define LEFT 2

#define RIGHT 3

#define RED 0

#define BLUE 1

void move(int d);

move(LEFT);

move(RIGHT);

move(BLUE); // Oops (legal)

{STOP, START, LEFT, RIGHT};

// equivalent to:

// const STOP = 0;

// const START = 1; …etc.

enum colors {RED, BLUE};

void move(directions d);

move(LEFT);

move(RIGHT);

move(BLUE); // Compile-time error

For giving symbolic names to numbers, you can use enum instead of #define; it even does type checking!