vue-router使用是报错. TypeError: Cannot read properties of undefined (reading ‘matched‘)

使用vue-router后，运行vue项目报错：

原代码：

import Vue from 'vue'
import App from './App.vue'
import VueRouter from "vue-router"
import routers from "./router/index"

Vue.config.productionTip = false;
Vue.use(VueRouter);

// router传参错误
new Vue({
  routers,
  render: h => h(App),
}).$mount('#app');

发现，自定义的路由文件导入必须用router来接收
修改后代码

import Vue from 'vue'
import App from './App.vue'
import VueRouter from "vue-router"
// 变量名只能用router
import router from "./router/index"

Vue.config.productionTip = false;

Vue.use(VueRouter);

// router <==> router: router
new Vue({
  router,
  render: h => h(App),
}).$mount('#app');