Number of 1 Bits

1class Solution {
2    public int hammingWeight(int n) {
3        int count = 0;
4        while (n != 0) {
5            int digit = n & 1;
6            if (digit == 1) {
7                count++;
8            }
9            n = n >> 1;
10        }
11        return count;
12    }
13}