isPalindrome.js

/**
 * @param {string} string
 * @return {boolean}
 */

export default function isPalindrome(string) {
  let left = 0;
  let right = string.length - 1;

  while (left < right) {
    if (string[left] !== string[right]) {
      return false;
    }
    left += 1;
    right -= 1;
  }

  return true;
}