Count Set Bits in an Integer

#include <stdio.h>

int countSetBits(unsigned int n) {
    //1. Bit shift n>> (while(n) means it loops until bit shifts to 0000 then stops)
    //2. & with 1, to check if first bit= 1
    //3. Increment counter
    int counter = 0;
    int bit_zero = -1;

    while(n){
        bit_zero = n & 0x01; 
        if(bit_zero){
            counter++;
        }
        n = (n >> 1);
    }
    return counter;
}

int main() {
    int n;
    scanf("%d", &n);
    printf("%d", countSetBits(n));
    return 0;
}