codewars第五篇（7kyu）Vowel Count

题目：
Return the number (count) of vowels in the given string.

We will consider a, e, i, o, and u as vowels for this Kata.

The input string will only consist of lower case letters and/or spaces.
个人感觉较好的解答：

function getCount(str) {
  return (str.match(/[aeiou]/ig)||[]).length;
}

function getCount(str) {
  return str.replace(/[^aeiou]/gi, '').length;
}

function getCount(str) {
 return str.split('').filter(c => "aeiouAEIOU".includes(c)).length;
}

自己的解答：

function getCount(str) {
  var vowelsCount = 0;
  var vowels = 'aeiou';
  for(var i = 0; i < str.length; i++){
    if(vowels.includes(str[i])){
      vowelsCount ++;
    }
  }
  return vowelsCount;
}