struct
struct bit{

int a;
int b;
int c;

};

int main(int argc, char *argv[])
{
bit s;
char *c = (char*)&s;
*c = 0x99;
cout << s.a << endl;
cout << s.b << endl;
cout << s.c << endl;
}
[解决办法]
结构体s没有初始化,所以abc的值都是随机值.
a是4字节的,*c = 0x99只会使a中一个字节变成0x99

至于a的值是0xXXXXXX99还是0x99XXXXXX得看大小端