longestWord.js

const regex = /\W|_/g;

function longest(acc, elem) {
  if (acc.length < elem.length && !regex.test(elem)) return elem;
  return acc
}

function longestWord(sen) {
  return sen.split(" ").reduce(longest, "");
}

function longestWord(sen) {
  const regex = /\W|_/g;
  const arr = sen.split(" ");
  let word = "";

  for (let i = 0; i < arr.length; i++) {
    const currentWord = arr[i];
    if (word.length < currentWord.length && !regex.test(currentWord))
      word = currentWord;
  }

  return word;
}