09-palindrome-number.js

/**
 * @param {number} x
 * @return {boolean}
 */
var isPalindrome = function (x) {
  if (x < 0 || (x % 10 === 0 && x !== 0)) return false;
  let reverted = 0;
  while (x > reverted) {
    reverted = reverted * 10 + (x % 10);
    x = Math.floor(x / 10);
  }
  return x === reverted || x === Math.floor(reverted / 10);
};