17. Extract the Nibble from an 8-bit Register

#include <stdio.h>

unsigned char extractNibble(unsigned char reg, int pos) {
    unsigned char upper,lower;// Write your code here
    if(pos)
    {
        upper = reg >>4 & 0x0F;
        return upper;
    }
    else
    {
        lower = reg & 0x0F;
        return lower;
    }
}

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