title: Codeigniter - Form validation converting post variables from Array to "Array" string
body: <p>I am building an HTML form with a set of checkboxes for selecting multiple categories using this format:</p>
  
  <pre>
  &lt;input type="checkbox" name="category[]" /&gt;
  </pre>
  
  <p>So, when I post and <code>print_r($_POST)</code> to view the variable and values I get:</p>
  
  <pre>
  Array
  (
      [27] => on
      [28] => on
      [29] => on
  )
  </pre>
  
  <p>Once I run <code>$this-&gt;form_validation-&gt;run();</code> the categories array becomes "Array" as a string.  I believe I have narrowed it down to "prep_for_form" function in the system/libraries/Form_validation.php file, but it seems like the recursive function is working correctly.</p>
  
  <p>Thank you in advance.</p>