Swap bits in a number in C [duplicate]

Answer 1

/*swaping four bits*/
#include

void printb(char a) {
    int i;
    for( i = 7; i >= 0; i--)
        printf("%d", (1 &  (a >> i)));
    printf("\n");
}

int swap4b(char a) {
    return ( ((a & 0xf0) >> 4) | ((a & 0x0f) << 4) );
}


int main()
{
    char a = 10;
    printb(a);
    a = swap4b(a);
    printb(a);
    return 0;
}