Remove or add character to make a string palindrome

makePalindrome.js

function isPalindrome(str) {
  let low = 0;
  let high = str.length - 1;
  while (low < high) {
    if (str[low] !== str[high]) return false;
    low++;
    high--;
  }
  return true;
}

function makePalindrome(str) {
  for (let i = 0; i < str.length; i++) {
    const newStr = str.slice(0, i) + str.slice(i + 1);
    if (isPalindrome(newStr)) {
      return newStr;
    }
  }
  return "Cannot make a palindrome";
}

console.log(makePalindrome("racecar")); //racecar
console.log(makePalindrome("madamy")); //madam
console.log(makePalindrome("mada")); //ada