palindrome.js

/**
 * @param {number} x
 * @return {boolean}
 */
var isPalindrome = function(x) {

    if (x < 0) return false

    let reverseData = 0, y = x

    while (y > 0) {
        const lastDigit = y % 10
        reverseData = (reverseData * 10) + lastDigit
        y = (y / 10) | 0
    }
    return x === reverseData
}


isPalindrome(111)