just simple how 2 find anagrams

anagram.js

// space complexity: O(n) -- the hashmap
// time complexity: ~O(2n); iterate both strings once
// worse case: O(2n)
function areAnagrams(a, b) {
  var len = a.length, chars = {}, i = 0;
  if (len !== b.length) return false;
  
  for(; i < len; i++) {
    chars[a[i].toLowerCase()] = true;
  }
  
  for(i = 0; i<len; i++) {
    if (!chars[b[i]].toLowerCase()) return false;
  }
  
  return true;
}