Longest Palindrome LeetCode solution in JavaScript

1
var longestPalindrome = function (s) {
2
  const hashMap = {};
3
  let ouput = 0;
4
  let hashOdd = false;
5

6
  for (let i = 0; i < s.length; i++) {
7
    if (!hashMap[s[i]]) {
8
      hashMap[s[i]] = 0;
9
    }
10
    hashMap[s[i]] += 1;
11
  }
12

13
  Object.values(hashMap)?.forEach((character) => {
14
    ouput += character % 2 ? character - 1 : character;
15
    if (character % 2 && !hashOdd) {
16
      hashOdd = true;
17
    }
18
  });
19

20
  return ouput + (hashOdd ? 1 : 0);
21
};