title: Add class to li with specific ID
body: <p>I want to add a class to a li with specific Id. I tried this:</p>
  
  <pre><code>function updateIndex(indexValue){
      $('li[id=' + indexValue + ']').addClass("selectedQuestion")
  
  }
  </code></pre>
  
  <p>I am not able to access indexValue variable in the li selector.</p>