enum BOOLEAN { FALSE = 0, TRUE } match_flag;
void main（）
{
int index = 0;
int count_of_letter = 0;
int count_of_space = 0;
char str[] = "I'm Ely efod";
match_flag = FALSE;
for（； str[index] != '/0'; index++）
if（ SPACE != str[index] ）
count_of_letter++;
else
{
match_flag = （enum BOOLEAN） 1;
count_of_space++;
}
printf（"%s %d times %c", match_flag "match" : "not match", count_of_space, NEWLINE）；
printf（"count of letters: %d %c%c", count_of_letter, NEWLINE, RETURN）；
}
输出：
match 2 times
count of letters: 10
Press any key to continue
4. 枚举类型与sizeof运算符
#include <stdio.h>
enum escapes
{
BELL = '/a',
BACKSPACE = '/b',
HTAB = '/t',
RETURN = '/r',
NEWLINE = '/n',
VTAB = '/v',
SPACE = ' '
};
enum BOOLEAN { FALSE = 0, TRUE } match_flag;
void main（）
{
printf（"%d bytes /n", sizeof（enum escapes））； //4 bytes
printf（"%d bytes /n", sizeof（escapes））； //4 bytes
printf（"%d bytes /n", sizeof（enum BOOLEAN））； //4 bytes
printf（"%d bytes /n", sizeof（BOOLEAN））； //4 bytes
printf（"%d bytes /n", sizeof（match_flag））； //4 bytes
printf（"%d bytes /n", sizeof（SPACE））； //4 bytes
printf（"%d bytes /n", sizeof（NEWLINE））； //4 bytes
printf（"%d bytes /n", sizeof（FALSE））； //4 bytes
printf（"%d bytes /n", sizeof（0））； //4 bytes
}
5. 综合举例
#include<stdio.h>
enum Season
{
spring, summer=100, fall=96, winter
};
typedef enum
{
Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday
}
Weekday;
void main（）
{
/* Season */
printf（"%d /n", spring）； // 0
printf（"%d, %c /n", summer, summer）； // 100, d
printf（"%d /n", fall+winter）； // 193
Season mySeason=winter;
if（winter==mySeason）
printf（"mySeason is winter /n"）； // mySeason is winter
int x=100;
if（x==summer）
printf（"x is equal to summer/n"）； // x is equal to summer
printf（"%d bytes/n", sizeof（spring））； // 4 bytes
/* Weekday */
printf（"sizeof Weekday is: %d /n", sizeof（Weekday））； //sizeof Weekday is: 4
Weekday today = Saturday;
Weekday tomorrow;
if（today == Monday）
tomorrow = Tuesday;
else
tomorrow = （Weekday） （today + 1）； //remember to convert from int to Weekday
}