title: How to check if a scope variable is undefined in AngularJS template?
body: <p>How to check if a scope variable is <em>undefined</em>?</p>
  
  <p>This does not work:</p>
  
  <pre><code>&lt;p ng-show="foo == undefined"&gt;Show this if $scope.foo == undefined&lt;/p&gt;
  </code></pre>