title: Angular expression if array contains
body: <p>I'm trying to add a class to an element if a <code>jobSet</code> has not been selected for approval using expressions.</p>
  
  <pre><code>&lt;li class="approvalUnit" ng-repeat="jobSet in dashboard.currentWork" ng-class="{-1:'approved'}[selectedForApproval.indexOf(jobSet)]"&gt;
  </code></pre>
  
  <p>This isn't exactly a fool proof method.  Any suggestions on how I should do this?</p>