3.DI（依存性注入）

var app = angular.module('MainApp', []);

app.controller('MainCtrl', ['$scope','MainFactory', 
  function($scope, MainFactory) {
      $scope.message = MainFactory.getName();
  }
]);

app.factory('MainFactory', [ 
  function($scope) {
    mainFactory = {};
    mainFactory.getName = function() {
      return 'AngularJS';
    }
    
    return mainFactory;
  }
]);

<!DOCTYPE html>
<html ng-app="MainApp">

  <head>
    <meta charset="utf-8" />
    <title>AngularJS Plunker</title>
    <script>document.write('<base href="' + document.location + '" />');</script>
    <link rel="stylesheet" href="style.css" />
    <script data-require="angular.js@1.4.x" src="https://code.angularjs.org/1.4.8/angular.js" data-semver="1.4.8"></script>
    <script src="app.js"></script>
  </head>

  <body ng-controller="MainCtrl">
    <p ng-bind="message"></p>
  </body>

</html>

/* Put your css in here */