1.代码

<script src="https://unpkg.com/vue@next" rel="external nofollow" ></script>
<div id="conditional-rendering"><span v-if="seen">现在你看到我了</span>
</div>
<script>
const ConditionalRendering = {data() {return {seen: true}}
}
Vue.createApp(ConditionalRendering).mount('#conditional-rendering')
</script>

2.运行结果