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

reverse-integer.js

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

let result = 0
let number = Math.abs(x)
for (let i of [...new Array(number.toString().length)].map((e, index) => Number("1" + "0".repeat(index))).reverse()) {
    result += (number % 10) * i
    number = Math.floor(number / 10)
 }
result = x<0 ? -result : result
if (result <= 2**31 -1 && result>= Math.pow(-2, 31)) {
    return result
   } else {
    return 0
  }
   
};

const reverse = x => {
    const limit = 2147483648;
    const k = x < 0 ? -1 : 1;
    const n = Number(String(Math.abs(x)).split('').reverse().join(''));
    return n > limit ? 0 : n * k;
};

this solution seems very straightforward