Extract the Nibble from an 8-bit Register

Code

#include <stdio.h>

unsigned char extractNibble(unsigned char reg, int pos) {
    unsigned char val;
    if(pos==0){
        val=reg & 0x0f;
        return val;
    }
    if(pos==1){
        val=reg >>4;
        return val;
    }
}

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

Solving Approach