npm install vue-router

"dependencies": {
  "vue-router": "^3.6.5"
},

src/router/index.js

import Vue from 'vue'
import Router from 'vue-router'
import Demo1 from '../components/Demo1'
Vue.use(Router);
// 設(shè)置組件映射規(guī)則
const routes = [
    {
        path: "/",
        redirect: "/demo1"
    },
    {
        path: '/demo1',
        component: Demo1
    }, {
        path: '/demo2',
        component: (resolve) => require(['@/components/Demo2'], resolve)
    }
]
export default new Router({
    routes
})

import Vue from 'vue'
import App from './App.vue'
import router from './router'
Vue.config.productionTip = false
new Vue({
    render: h => h(App),
    router
}).$mount('#app')

<template>
  <div id="app">
    <img alt="Vue logo" src="./assets/logo.png">
    <HelloWorld msg="Welcome to Your Vue.js App"/>
    <router-view/>
  </div>
</template>
<script>
import HelloWorld from './components/HelloWorld.vue'
export default {
  name: 'App',
  components: {
    HelloWorld
  }
}
</script>
<style>
#app {
  font-family: Avenir, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-align: center;
  color: #2c3e50;
  margin-top: 60px;
}
</style>

<router-view/>

<template>
  <div>這是 demo1.vue</div>
</template>
<script>
export default {
  name: "Demo1"
}
</script>
<style scoped>
</style>