hidden and show in html code example

Example 1: html hidden

<!-- stops an element from rendering, but still loads it to memory-->
<p>this will show</p>
<p hidden>Thill will not show</p>

Example 2: how to change hidden on html

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<table>
  <tr>
    <td>
      <input id="check" type="checkbox" name="del_attachment_id[]" value="<?php echo $attachment['link'];?>">
    </td>

    <td id="delete" hidden="true">
      the file will be deleted from the newsletter
    </td>
  </tr>
</table>