find all vowels in string js code example

Example 1: how to make a vowel counter in javascript

function countVowels(str) {
  return str.match(/[aeiou]/g).length;
}

Example 2: count vowels in a string javascript

// BEST and FASTER implementation using regex
const countVowels = (str) => (str.match(/[aeiou]/gi) || []).length