Algorithms in Javascript: CTCI 1.4 Palindrome Permutation: Given a string, determine if it is a permutation of a palindrome.

ctci-1.4-is-string-a-palindrome.js

const isPalindrome = (s1) => {
  let charMap = new Map();
  for(let i=0; i <s1.length; i++){
    if(charMap.get(s1[i])) {
      charMap.delete(s1[i]);
    } else {
      charMap.set(s1[i], 1);
    }
  }
  if(s1.length%2 === 0 && charMap.size === 0 ||
    s1.length%2 === 1 && charMap.size === 1) {
    return true;
  }
  return false;
}

let x = 'abbc';
console.log(isPalindrome(x));