17. Extract the Nibble from an 8-bit Register

#include <stdio.h>

unsigned char extractNibble(unsigned char reg, int pos) {
 if (pos == 0) return reg & 0x0F;           //low nibble
 else if (pos == 1) return (reg >> 4 ) & 0x0F ;  //high nibble
 else return 0; //invalid nibble
}

int main() {
    unsigned char reg;
    int pos;
    scanf("%hhu %d", &reg, &pos);
    printf("%d", extractNibble(reg, pos));
    return 0;
}