title: Angular controller not register to module
body: <p>I am still new on angularjs and have a question: How does the controller still know which module it registerred to on code snippet below (found on the Angular official document):
  JS</p>
  
  <pre><code> angular.module('App', []);
      function Ctrl($scope) {
        $scope.val = 1234.56789;
      }
  </code></pre>
  
  <hr>
  
  <p>Html something like:</p>
  
  <pre><code>&lt;html ng-app="App"&gt;
  &lt;body&gt;
  &lt;div ng-controller="Ctrl"&gt;
   ........
  &lt;/div&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>I suspect there is something to do with bootstrap time and $scope available globally???</p>
  
  <p>Thank you very much</p>