191_Number_of_1_Bits.js

// https://leetcode.com/problems/number-of-1-bits/

/*
191. 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.
*/

/**
 * @param {number} n - a positive integer
 * @return {number}
 */
var hammingWeight = function(n) {
  var based2 = n.toString(2);
  var count = based2.split('').filter(function(ch) { return parseInt(ch); }).length;
  return count;
};