function isPalindrome(s, i, l) { for (let j = i, k = i + l - 1, h = Math.floor(l / 2); h > 0; h--, j++, k--) { if (s[j] !== s[k]) { return false; } } return true; } function getLongestPalindrome(s) { let palindrome = s[0]; for (let i = 0, n = s.length, m = n; i < n - 1; i++, m--) { for (let l = m; l > palindrome.length; l--) { if (isPalindrome(s, i, l)) { palindrome = s.substring(i, i + l); } } } return palindrome; } console.log(getLongestPalindrome("bannana"));