Reverse Integer// source https://jsbin.com/kororer

jsbin.kororer.js

/*
* Reverse Integer using Javascript ES6
* Built in JS methods: toString(), split(), reduce(), Math.sign()
*/
const reverseInt = (n, rev='', final) => {
  
  final = n.toString().split('').reduce((acc, inv) => rev = inv + acc, '');

  return parseInt(final) * Math.sign(n);
}

console.log(reverseInt(15)); // 51
console.log(reverseInt(981)); // 189
console.log(reverseInt(500)); // 5
console.log(reverseInt(-15)); // -51
console.log(reverseInt(-90)); // -9
console.log(reverseInt(0)); // 0