title: Get id of selected item in ng-option
body: <p>I would like to get the id of the selected item but <code>console.log</code> display <em>undefined</em>. </p>
  
  <p><strong>View</strong></p>
  
  <pre><code> &lt;select ng-change="test()" ng-model="selectedone" ng-options="item.id as item.pseudo for item in friends"&gt;&lt;/select&gt;
  </code></pre>
  
  <p><strong>Controller</strong></p>
  
  <pre><code>  $scope.test = function(){
          console.log($scope.selectedone);
      }
  </code></pre>