Anagrams in JavaScript

anagrams.js

//specs
anagrams('rail safety', 'fairy tales') // true
anagrams('RAIL SAFETY', 'fairy tales') // true
anagrams('hi there', 'bye there') // false

//solution 1
function anagrams(strA, strB) {
  const charMapA = buildCharMap(strA);
  const charMapB = buildCharMap(strB);

  if (Object.keys(charMapA).length !== Object.keys(charMapB).length) {
    return false;
  }

  for (let char in charMapA) {
    if (charMapA[char] !== charMapB[char]) {
      return false;
    }
  }

  return true;
}

function buildCharMap(str) {
  const charMap = {};
  for (let char of str.replace(/[^\w]/g,'')) {
    charMap[char] = charMap[char] + 1 || 1;
  }
  return charMap;
}

//solution 2
function anagrams(strA, strB) {
  return cleanString(strA) === cleanString(strB);
}

function cleanString(str) {
  return str.replace(/[^\w]/g,'').toLowerCase().split('').sort().join('');
}