main.js

'use strict';

// https://leetcode.com/problems/reverse-integer/

/**
 * @param {number} x
 * @returns {number}
 * @description Returns reversed integer
 */
var reverse = function (x) {
    let temp = Math.abs(x);
    let reversed = '';
    while (temp > 0) {
        reversed += (temp % 10);
        temp = parseInt(temp / 10);
    }

    reversed = Number(reversed) * (x / Math.abs(x));
    if (reversed > ((2 ** 31) - 1) || reversed < -(2 ** 31) || isNaN(reversed)) {
        return 0;
    }

    return reversed;
};

// // Another way to solve the same problem using built-in methods in JS
// var reverse = function (x) {
//     let tempNum = Math.abs(x).toString();
//     let tempArr = Array.from(tempNum);
//     let tempReversedArr = tempArr.reverse().join('');

//     const reversed = Number(tempReversedArr) * (x / Math.abs(x));
//     if (reversed > ((2 ** 31) - 1) || reversed < -(2 ** 31) || isNaN(reversed)) {
//         return 0;
//     }


//     return reversed;
// }

// console.log(reverse(123));  // 321
// console.log(reverse(120)); // 21
// console.log(reverse(-123)); // -321
// console.log(reverse(-987142)); // -241789
// console.log(reverse(214748364)); // 463847412