How to render the Vue object data created by Vue-cli

I created the simplest project with Vue-cli. I added a data attribute to the Vue instance in main.js, so why can"t it be displayed on the page? the same problem can occur in scenarios where webpack + vue-loader is used. Now all data can only be added to Component.

main.js

import Vue from "vue"
//import App from "./App.vue"

Vue.config.productionTip = false

new Vue({
    el: "-sharpapp",
    data() {
        return {
            msg: "Hello from Vue!"
        }
    },
    //render: h => h(App)
}).$mount("-sharpapp");

index.html

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width,initial-scale=1.0">
    <link rel="shortcut icon" href="<%= webpackConfig.output.publicPath %>favicon.ico">
    <title>vue-cli-example</title>
  </head>
  <body>
    <noscript>
      <strong>We"re sorry but vue-cli-example doesn"t work properly without JavaScript enabled. Please enable it to continue.</strong>
    </noscript>
    <div id="app">
      {{msg}}
    </div>
    <!-- built files will be auto injected -->
  </body>
</html>
Mar.09,2021

because this html is just for you to mount
vue scaffolding will not compile this html
they will only compile .vue single file component files
you can only write data properties in .vue

import Vue from 'vue'
import App from './App.vue'

Vue.config.productionTip = false

/* eslint-disable no-new */
new Vue({
  el: '-sharpapp',
  template: '<App/>',
  components: { App }
})

you can learn about this open source project build a large single page application with 45 pages based on vue2 + vuex

MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b30d22-2b290.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b30d22-2b290.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?