<script src="https://unpkg.com/vue@next"></script>
<script src="https://cdn.bootcdn.net/ajax/libs/vue/3.2.0-beta.7/vue.cjs.js"></script>

<!-- 1、挂载html标签的id上 -->
<div id="app">{{title}}</div>

<script>
    const app = Vue.createApp({
        data() {
            return {
            title: "我是欧阳克",
            };
        },
    }).mount("#app");
    // 可以用app变量访问标题
    console.log(app.title);
</script>

<!-- 2、执行方法 -->
<div id="app">{{title}} {{one()}}</div>

<script>
    const app = Vue.createApp({
        data() {
            return {
                title: "我是欧阳克"
            };
        },
        methods: {
            one() {
                console.log(this.title);
                return "我是one方法";
            }
        },
    }).mount("#app");

    console.log(app.title);
    console.log(app.one());
</script>