Displays vowels and number of vowels in a string using regex

VowelsInSTR.php

$str = "Created by PhpStorm.
 * User: Tounsi
 * Date: 30/10/2018
 * Time: 11:59
 * 
 * List of vowels in string";

$nbVowels = 0;
for($i=0;$i<strlen($str);$i++)
{
    $letter = $str[$i];
    if(preg_match('/[aeuioAEUIO]/',$letter)){
        $nbVowels++;
        echo $letter;
    }
}
echo "<br>number of vowels = $nbVowels :)";