Number of 1 Bits

Write a function that takes an unsigned integer and returns the number of ’1' bits it has (also known as the Hamming weight).

For example, the 32-bit integer ’11' has binary representation 00000000000000000000000000001011, so the function should return 3.

public class Solution {
    // you need to treat n as an unsigned value
    public int hammingWeight(int n) {
        long num = Long.MAX_VALUE & n;
        int countOfOne = 0;
        while(num != 0){
            countOfOne += Math.abs(num % 2);
            num /= 2;
        }
        
        return countOfOne;
    }
}