es6-code-refactor.js

const upperCaseFirstLetter = word => `${word[0].toUpperCase()}${word.slice(1)}`;
const upperCaseWords = s => s.split(" ").map(w => upperCaseFirstLetter(w)).join(" ");

console.log(upperCaseWords("code example to refactor"));

/*
or 


const upperCaseFirstLetter = word => `${word[0].toUpperCase()}${word.slice(1)}`;
const upperCaseWords = s => {
  let words = s.split(" ")
  for (let i = 0; i < words.length; i++) {
    words[i] = upperCaseFirstLetter(words[i]);
  }
  return words.join(" ");
}
console.log(upperCaseWords("code example to refactor"));

*/