17. Extract the Nibble from an 8-bit Register

#include <stdio.h>

unsigned char extractNibble(unsigned char reg, int pos) {
    // Write your code here
   unsigned char nibble;

    if (nibble == 0) {
        nibble= reg & 0x0F;
    }
    else{
        nibble == (reg & 0xF0)>>4;
    }
 
    return nibble;
}

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