title: Parsing error when trying to add class via state to list item element
body: <p>I have a React app and I am using the hooks useState and useCallback to control navigation between pages.</p>
  
  <p>That part works, but I want to highlight the current page link.</p>
  
  <p>So added a new state element called 'chosen' that is set with 'setChosen'.</p>
  
  <pre><code>const [chosen, setChosen] = useState();
  const [showGameViewer, setGamerViewer] = useState(false);
  const [showGameCreator, setGameCreator] = useState(false);
  </code></pre>
  
  <p>Then in my useCallback, I use setChosen:</p>
  
  <pre><code>const handleLinkMenuClick = useCallback(e =&gt; { setGamerViewer(false) || (setGameCreator(true) &amp;&amp; setChosen(true))});
  </code></pre>
  
  <p>My links look like this, I am trying to append the CSS class called "current" to the className:</p>
  
  <pre><code>&lt;li className="nav-item " {chosen &amp;&amp; "current"}&gt;
      &lt;a className="nav-link" href="#" onClick={handleLinkMenuClick}&gt;Show Game Creator&lt;/a&gt;
  &lt;/li&gt;
  </code></pre>
  
  <p>And my css:</p>
  
  <pre><code>.chosen {
      background: yellow;
  }
  </code></pre>
  
  <p>But I am getting an error for the above code {chosen &amp;&amp; "current"} that says:</p>
  
  <pre><code>const chosen is undefined. Parsing Error: Unexpected token
  </code></pre>
  
  <p>I'm not sure why it's saying that.  I have 'chosen' defined above.  So it should know.</p>
  
  <p>Does anyone see anything wrong? </p>