JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://unpkg.com/vue/dist/vue.js"></script>
    <body>
        <div id="main-container">
            <div id="contact-table">
                <table>
                    <thead>
                        <tr>
                            <th>Contact Name</th>
                            <th>Email</th>
                        </tr>
                    </thead>
                    <tbody v-for="(contact, index) in contacts">
                        <tr v-on:click="selectContact(index)">
                            <td>
                                {{contact.name}}
                            </td>
                            <td>
                                {{contact.email}}
                            </td>
                        </tr>
                    </tbody>
                </table>
            </div>
            <div id="contact-form">
                <input type="text" v-model="contactName"/>
                <input type="text" v-model="contactEmail"/>
                <button type="button" v-on:click="updateContact">Update Contact</button>
            </div>
        </div>
    </body>
    <script>
        var hub = {
            contacts: [
                {
                    name: "James",
                    email: "[email protected]",
                    index: 0
                },
                {
                    name: "Mary",
                    email: "[email protected]",
                    index: 1
                }
            ],
            index: 0
        };
        
        var bus = new Vue() 
        var contactTable = new Vue({
            el: "#contact-table",
            data: {
                contacts: hub.contacts
            },
            methods: {
                selectContact: function(index) {
                    hub.index = index;
                    console.log(hub.index);
                    bus.$emit('updateIndex', index)
                }
            }
        });

        var contactForm = new Vue({
       ...