test 1

index1.php

<?php

function vocal($string = "")
{
   $string = str_split(str_replace(" ", "", strtolower($string)));
   $vocal = "aiueo";
   $result = [];

   foreach ($string as $key => $value) {
      if (str_contains($vocal, $value)) {
         array_push($result, $value);
      }
   }

   sort($result);
   return implode("", $result);
}

/**
 * remove vowel char return sort character
 *
 * @param array $string
 * @return void
 */
function konsonan($string = "")
{
   $string = str_split(str_replace(" ", "", strtolower($string)));
   $vocal = "aiueo";
   $result = [];

   foreach ($string as $key => $value) {
      if (!str_contains($vocal, $value)) {
         array_push($result, $value);
      }
   }
   ksort($result);
   return implode("", $result);
}

function main($string = "")
{
   echo vocal($string) . "<br>";
   echo konsonan($string) . "<br>";
}

main("sample case");