title: Find the number of <td>s in a <tr> without using id or name
body: <p>How do you calculate the number of <code>&lt;td&gt;</code> elements in a particular <code>&lt;tr&gt;</code>?</p>
  
  <p>I didn't specify id or name to access directly, we have to use the <code>document.getElementsByTagName</code> concept.</p>