angularjs route不起作用参数'CatCtrl'不是函数，未定义

I below app.js file

我在app.js文件下面

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

app.config(['$routeProvider', function ($routeProvider) {
    $routeProvider.
        when('/categories', {
            templateUrl: 'views/cat.view.html',
            controller: 'CatCtrl'
        })
    }]);
var app =