将一个字节反转

#include <stdio.h>

int main()
{
    unsigned char a = 0xaa, b = 0;
    char i = 0;
    for (i = 0; i < 8; i++)
    {
        b |= (((a >> i) & 0x01) << (7 - i));
    }
    printf("b = 0x%x
", b);
    return 0;
}