isAnagram

Checks if a string is an anagram of another string (case-insensitive, ignores spaces, punctuation and special characters).

• Use String.prototype.toLowerCase() and String.prototype.replace() with an appropriate regular expression to remove unnecessary characters.
• Use String.prototype.split(''), Array.prototype.sort() and Array.prototype.join('') on both strings to normalize them, then check if their normalized forms are equal.

const isAnagram = (str1, str2) => {
  const normalize = str =>
    str
      .toLowerCase()
      .replace(/[^a-z0-9]/gi, '')
      .split('')
      .sort()
      .join('');
  return normalize(str1) === normalize(str2);
};

isAnagram('iceman', 'cinema'); // true