How to find longest palindrome of a string in JavaScript?

bvl9h3f.js

var longestPalindrome = function(s) {
    if (isPalindrome(s)) {
        return s;
    }
    
    var maxP = s[0];
    
    for (var i=0; i < s.length; i++) {
        var curr = s[i];
        for (var j= i + 1; j < s.length; j++) {
            curr += s[j];
            if (isPalindrome(curr) && curr.length > maxP.length) {
                maxP = curr;
            }
        }
    }
    return maxP;
};

function isPalindrome(s, i) {
    return(i=i||0)<0||i>=s.length>>1||s[i]==s[s.length-1-i]&&isPalindrome(s,++i);
}

console.log(longestPalindrome('kayak tacocat racecar tattarrattat wow')); // --> "tattarrattat" 

// https://jsfiddle.net/vovchuck_bogdan/yv6u9d1u/2/