--description--

Given a string, determine if it's a palindrome and return the middle character (if it's odd length) or middle two characters (if it's even).

• A palindrome is a string that is the same forward and backward.
• If it's not a palindrome, return "none".

--hints--

palindromeLocator("racecar") should return "e".

assert.equal(palindromeLocator("racecar"), "e");

palindromeLocator("level") should return "v".

assert.equal(palindromeLocator("level"), "v");

palindromeLocator("freecodecamp") should return "none".

assert.equal(palindromeLocator("freecodecamp"), "none");

palindromeLocator("noon") should return "oo".

assert.equal(palindromeLocator("noon"), "oo");

palindromeLocator("11100111") should return "00".

assert.equal(palindromeLocator("11100111"), "00");

--seed--

--seed-contents--

function palindromeLocator(str) {

  return str;
}

--solutions--

function palindromeLocator(str) {
  if (str !== str.split("").reverse().join("")) return "none";

  const mid = Math.floor(str.length / 2);
  return str.length % 2 === 1 ? str[mid] : str[mid - 1] + str[mid];
}