how to capitalize every first letter in javascript code example

Example 1: javascript uppercase first character of each word

const uppercaseWords = str => str.replace(/^(.)|\s+(.)/g, c => c.toUpperCase());

// Example
uppercaseWords('hello world');      // 'Hello World'

Example 2: js capitalize first letter of each word

function capitalize(str) {
  const arrOfWords = str.split(" ");
  const arrOfWordsCased = [];

  for (let i = 0; i < arrOfWords.length; i++) {
    const word = arrOfWords[i];
    arrOfWordsCased.push(word[0].toUpperCase() + word.slice(1).toLowerCase());
  }

  return arrOfWordsCased.join(" ");
}