<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Example</title>
</head>
<body>
    <div id="app">
        <p>{{ message }}</p>
        <button v-on:click="reverseMessage">메시지 뒤집기</button>
    </div>
    <script src="app.js"></script>
</body>
</html>

new Vue({
    el: '#app',
    data: {
        message: 'Hello, Vue.js!'
    },
    methods: {
        reverseMessage: function() {
            this.message = this.message.split('').reverse().join('');
        }
    }
});