title: How to toggle between two string values like boolean True/False inside AngularJS?
body: <p>I have a button, clicking on it should show/hide some area.</p>
  
  <pre><code>button(ng-click="areaStatus='on'")
  .area(ng-class="areaStatus")
  </code></pre>
  
  <p>I want not to just use ng-show/ng-hide and then assign it to Boolean areaStatus, but I want more complex things like on/off/hidden/transparent/whatever.</p>
  
  <p>Is there a way to toggle areaStatus between 'on' and 'off' on click without having to write a function for it, just with an inline expression?</p>