意外聊天过滤输出

Question

I expect the output of *****, but the actual output is a dummy

<?php
  ini_set('display_errors', 1);
  ini_set('display_startup_errors', 1);
  error_reporting(E_ALL);

  function filterwords($text){
  $filterWords = array("test","randomText","dummy");
  $filterCount = sizeof($filterWords);
 for($i=0; $i<$filterCount; $i++){
  $text = str_replace($filterWords[$i],"*****",$text);
 }
 return $text;
}
echo filterwords('dummy');
?>

All help is appreciated thanks