JavaScript/String/CountVowels.js

/**
 * @function countVowels
 * @description Given a string of words or phrases, count the number of vowels.
 * @param {String} str - The input string
 * @return {Number} - The number of vowel 
 * @example countVowels("ABCDE") => 2
 * @example countVowels("Hello") => 2
 */

const countVowels = (str) => {
  if (typeof str !== 'string') {
    throw new TypeError('Input should be a string');
  }

  const vowelRegex = /[aeiou]/gi;
  const vowelsArray = str.match(vowelRegex) || [];

  return vowelsArray.length;
}

export { countVowels };