17. Extract the Nibble from an 8-bit Register

#include <stdio.h>

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

// 8 bits : upper nibble (4 bits contains MSB) | lower nibble (4 bits contain LSB)

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