结构体要注意位补齐（有4位补齐和8位补齐，默认8位）
1 #include<stdio.h> 2 #pragma pack(push) 3 #pragma pack(4) 4 struct test 5 { 6 7 char a; //补3位 8 long c; 9 char d; 10 char h;//补2位 11 int b; 12 char e; //补3位或补7位 13 double f; 14 char g; //补3位或补7位 15 }s1; 16 #pragma pack(pop) 17 18 typedef struct{ 19 double a; 20 char b; 21 }s2; 22 23 union test2 24 { 25 char a; 26 short b; 27 }s3; 28 29 enum week{sun=7,mon=1,tue,wed,thu,fri,sta}; 30 enum week weekday; 31 32 void main(void) 33 { 34 printf("s1:%d ",sizeof(s1)); 35 printf("s2:%d ",sizeof(s2)); 36 printf("s3:%d ",sizeof(s3)); 37 printf("week:%d ",sizeof(weekday)); 38 }
以下是运行结果
