the longest word in javascript

longer-word.js

'use strict';
const str = 'example example2 proof guide';
const arr = str.split(' ');
const arrLength = [];

for (let i of arr) arrLength.push(i.length);

const max = Math.max.apply(null, arrLength);

for (let i = 0; i < arr.length; i++) {
  if (max === arr[i].length) console.log(arr[i]);
}