title: array_walk_recursive to apply function to each array element not working at all
body: <p>I have the following code on a form page:</p>
  
  <pre><code>array_walk_recursive($_POST, 'sanitize');
  </code></pre>
  
  <p>It is used so I can echo the $_POST variables inside of each form field after a user submits a form.</p>
  
  <p>Here is the <code>sanitize</code> function:</p>
  
  <pre><code>function sanitize ($v) {
      return htmlspecialchars(trim($v), ENT_QUOTES);
  }
  </code></pre>
  
  <p>It is not working whatsoever. The $_POST array still contains harmful quotation marks that breaks form elements on the page when I enter something like '"> break' for the value.</p>
  
  <p>Any help would be greatly appreciated.</p>