17. Extract the Nibble from an 8-bit Register

#include <stdio.h>

unsigned char extractNibble(unsigned char reg, int pos) {
     // Binary: 1010 1011
    if (pos==0){
    // Extract lower nibble (B)
    unsigned char lower = reg & 0x0F;
    return lower;}
    else{
    // Extract upper nibble (A)
    unsigned char upper = (reg >> 4) & 0x0F;
    return upper;}
    
}

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