title: regex to match only 5 letter words
body: <p>I have an array and want to retrieve only 5 letter words, nothing longer, I have tried to use</p>
  
  <pre><code>$new = preg_grep("/.{5}/", $array);
  </code></pre>
  
  <p>but that resulted in any word that is at least 5 letters long.  I want any word that is at most 5 letters long.</p>