ucwords.js

let ucwords = (str) => {
  return str.toLowerCase()
            .split(' ')
            .map((x) => x.slice(0, 1).toUpperCase() + x.slice(1, x.length))
            .join(' ');
}

let tes = ucwords("loReM iPsum DolOr SIt aMet");
console.log(tes); // result: "Lorem Ipsum Dolor Sit Amet"