Anagrams

anagrams.js

function anagrams(stringA, stringB) {
  const aCharMap = charMap(stringA.replace(/[^\w]/g, '').toLowerCase());
  const bCharMap = charMap(stringB.replace(/[^\w]/g, '').toLowerCase());
  
  // return false immediately when the length of two char Map is not the same
  if (Object.keys(aCharMap).length !== Object.keys(bCharMap).length) {
    return false;
  }

   // comparison
  for (let char in aCharMap) {
    if (aCharMap[char] !== bCharMap[char]) {
      return false;
    }
  }

  return true;
}

// helper function
function charMap(str) {
  let charMap = {};
  for (let char of str) {
    charMap[char] = charMap[char] + 1 || 1;
  }
  return charMap;
}