In this example you can see solving palindrom numbers in another way.

palindrom_integer_v_0.1.js

/**
 * @param {number} x
 * @return {boolean}
 */
var isPalindrome = function(x) {
let sum = 0, n, m = x;
    if (x < 0) return false;
while (x != 0 ) {
    sum = sum * 10 + x % 10;; 
    x = Math.floor (x / 10);
}
return sum == m ? true : false;
};