Extract the Nibble from an 8-bit Register

Code

#include <stdio.h>

unsigned char extractNibble(unsigned char reg, int pos) {
    if (pos == 0) { // extract lower nibble
        reg = reg & 0b00001111;
    }
    else if (pos == 1) { // extract upper nibble
        reg = ((reg & 0b11110000) >> 4);
    }
    return reg;
}

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

Solving Approach