常量类型

 1 #include <stdio.h>
 2 
 3 //1. 预编译
 4 #define PI 3.14
 5 
 6 int main(void)
 7 {
 8 //2. const关键字
 9     const int LENGTH = 100;
10 
11 //3. 枚举类型
12     enum color {
13         RED,
14         GREEN,
15         BLUE
16     };  
17     printf("pi = %f\n", PI);
18     printf("length = %d\n", LENGTH);
19     printf("red  = %d\n", RED);
20     printf("green = %d\n", GREEN);
21     printf("blue  = %d\n", BLUE);
22 }