javascript - 未捕获的 TypeError : Cannot set property 'app' of undefined Vue. js

Question

我想使用 Laravel 5.4 和 Vue2 设置一个 SPA。我有一个教程(Jeffrey Way - Laracast)。但我遇到了这个问题。无法弄清楚为什么控制台中出现此错误？ :

Uncaught TypeError: Cannot set property 'app' of undefined
    at VueRouter (app.js:3149)
    at Object.<anonymous> (app.js:4266)
    at __webpack_require__ (app.js:20)
    at Object.<anonymous> (app.js:3343)
    at __webpack_require__ (app.js:20)
    at Object.<anonymous> (app.js:13749)
    at __webpack_require__ (app.js:20)
    at app.js:66
    at app.js:69

下面是我的代码:

应用程序.js

import router from './routes';

import './bootstrap';

var app = new Vue({
    el: '#root',
    router
});

路由.js

import VueRouter from 'vue-router';

let routes = [
        {
            path: '/',
            component: require('./views/Home')
        }
    ];

export default VueRouter({
    routes
});

Bootstrap .js

import Vue from 'vue';
import VueRouter from 'vue-router';
import axios from 'axios';

window.Vue = Vue;
window.axios = axios;
Vue.use(VueRouter);

window.axios.defaults.headers.common = {
    'X-CSRF-TOKEN': window.Laravel.csrfToken,
    'X-Requested-With': 'XMLHttpRequest'
};

Answer 1

export default new VueRouter({
  routes
});

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