title: Which 'li' was clicked using vanilla JS
body: <p>I have some li elements:</p>
  
  <pre><code>&lt;ul&gt;
    &lt;li&gt;One&lt;/li&gt;
    &lt;li&gt;Two&lt;/li&gt;
    &lt;li&gt;Three&lt;/li&gt;    
  &lt;/ul&gt;
  </code></pre>
  
  <p>I need to know the number of the element that was clicked. For example, if an user clicks on </p>
  
  <pre><code>&lt;li&gt;Three&lt;/li&gt;
  </code></pre>
  
  <p>my output will be "3". </p>
  
  <p><br>
  How can I get this result using vanilla JavaScript?</p>