how to make a vowel counter in javascript

1const vowelCount = str => {
2  let vowels = /[aeiou]/gi;
3  let result = str.match(vowels);
4  let count = result.length;
5
6  console.log(count);
7};

1function getCount(str) {
2let vowelList = 'AEIOUaeiou'
3let vowelsCount = 0;
4
5 for(var i = 0; i < str.length ; i++)
6  {
7    if (vowelList.indexOf(str[i]) !== -1)
8    {
9      vowelsCount += 1;
10    }
11  }
12  return vowelsCount;
13}
14

1function countVowels(str) {
2  return str.match(/[aeiou]/g).length;
3}