<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>

    </style>
</head>
<body>
    <div id="app" v-cloak>
        <h2 >{{a}}</h2>
        <button @click="add">点击加1</button>
    </div>
    <script src = "js/vue.js"></script>
    <script>
        var vue = new Vue({
            el: "#app",
            data: {
                a: 100
            },
            methods:{
                add(event) {
                    console.log(event)
                }
            }
        })
    </script>
</body>
</html>

vue指令：v-on（@click）绑定点击事件，也就是方法_javascript