var app;
app = new Vue({
el: "#app",
data: {
value: "hello world",
}
});Vue.component('login', {
template: '<h1>login</h1>'
})<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Daemon</title>
<script src="./js/jquery-3.2.1.js" charset="UTF-8"></script>
<script src="./js/semantic.min.js" charset="UTF-8"></script>
<script src="./js/vue.js" charset="UTF-8"></script>
<link rel="stylesheet" href="./css/semantic.min.css">
</head>
<body>
<p id="app">
<p class="ui container">
<p class="ui pider"></p>
<p class="ui blue button">
{{value}}
</p>
<login></login>
</p>
</p>
<script src="./js/global.js" charset="UTF-8"></script>
<script src="./js/login.js" charset="UTF-8"></script>
</body>
</html>結果報錯:[Vue warn]: Unknown custom element: <login> - did you register the component correctly? For recursive components, make sure to provide the "name" option.#e#(found inlt; ;)
html中我做了修改，調整了js引入的順序，因為需要在保證app根元件渲染的時候，其中用到的元件已經聲明註冊。
全域API系列都必須在實例化之前申明