var isPalindrome = function(s) {

let leftPointer = 0;

let rightPointer = s.length - 1;

while (leftPointer < rightPointer) {

while (leftPointer < rightPointer && !(alphaNumChecker(s[leftPointer]))) {

leftPointer++;

}

while (rightPointer > leftPointer && !(alphaNumChecker(s[rightPointer]))) {

rightPointer--;

}

if (toLowerCase(s[leftPointer]) !== toLowerCase(s[rightPointer])) {

return false;

}

leftPointer++;

rightPointer--;

}

return true;

};

var alphaNumChecker = function(char) {

if (!(char > 47 && char < 58) && // numeric (0-9)

!(char > 64 && char < 91) && // upper alpha (A-Z)

!(char > 96 && char < 123)) { // lower alpha (a-z)

return false;

}

return true;

}

var toLowerCase = function(code) {

if (code >= 65 && code <= 90) {

return code + 32

}

else {

return code

}

}

This is what I got so far using a neetcode tutorial as a guide which is done in Python. This is JS of course. It runs true on "race a car" and I'm not sure why. Spent like 2 hours trying different things, obviously it's not detecting two letters are not the same for some reason.