title: How to use clsx in React
body: <p>I am trying to understand some uses of clsx in assigning classnames to a component in React.</p>
  
  <p>The construct </p>
  
  <pre><code>className={clsx(classes.menuButton, open &amp;&amp; classes.hide)} 
  </code></pre>
  
  <p>is clear enough. It applies 'classes.menuButton', and also applies 'classes.hide' if the value of the boolean 'open' is true.</p>
  
  <p>My question relates to this second example:</p>
  
  <pre><code>className={clsx(classes.appBar, {[classes.appBarShift]: open })}
  </code></pre>
  
  <p>This will apply 'classes.appBar'. But what is the meaning of the second parameter?</p>