Demo vuejs là gì? Viết chương trình đầu tiên Live code

<!DOCTYPE html>
<html>

<body>
    <div class="container" id="app-demo" style="margin-top: 40px;">
        <div class="row">
            <div class="col-sm-8 col-sm-offset-2">
                <div class="panel panel-info">
                    <div class="panel-heading">
                        <h3 class="panel-title">Vue Demo</h3>
                        <button type="button" class="btn btn-info pull-right" data-toggle="modal" data-target="#myModal"><i class="glyphicon glyphicon-plus"></i></button>
                        <form action="" method="POST" role="form">
                            <div class="form-group">
                                
                                <input type="text" class="form-control" id="" v-model="search" placeholder="Type content...">
                            </div>
                        </form>
                    </div>
                    <div class="panel-body">
                        <div class="table-responsive">
                            <table class="table table-hover">
                                <thead>
                                    <tr>
                                        <th>Name</th>
                                        <th>Age</th>
                                        <th>Class</th>
                                        <th>Action</th>
                                    </tr>
                                </thead>
                                <tbody>
                                    <tr v-for="(person, index) in searchs">
                                        <td>{{ person.name }}</td>
                                        <td>{{ person.age }}</td>
                                        <td>{{ person.class }}</td>
                                        <td>
                                            <button type="buton" v-on:click="updateStudent(index)" class="btn btn-info" data-toggle="modal" data-target="#myModalu"><i class="glyphicon glyphicon-pencil"></i></button>
                                            <button type="buton" v-on:click="deleteStudent(index)" class="btn btn-danger"><i class="glyphicon glyphicon-trash"></i></button>
                                        </td>
                                    </tr>
                                </tbody>
                            </table>
                        </div>
                    </div>
                </div>
            </div>
        </div>
        <div id="myModal" class="modal fade" role="dialog">
            <div class="modal-dialog">
                
                <div class="modal-content">
                    <div class="modal-header">
                        <button type="button" class="close" data-dismiss="modal">×</button>
                        <h4 class="modal-title">Add students</h4>
                    </div>
                    <div class="modal-body">
                        <form action="" method="POST" role="form" v-on:submit.prevent="addStudent">
                            <form action="" method="POST" role="form" v-on:submit.prevent="updateStudent">
                                <div class="form-group">
                                    <label for="">Name</label>
                                    <input type="text" class="form-control" v-model="student.name" required="" id="" placeholder="Name...">
                                </div>
                                <div class="form-group">
                                    <label for="">Age</label>
                                    <input type="number" class="form-control" v-model="student.age" id="" required="" placeholder="Age...">
                                </div>
                                <div class="form-group">
                                    <label for="">Class</label>
                                    <input type="text" class="form-control"  v-model="student.class" required="" id="" placeholder="Class...">
                                </div>
                                <button type="submit"  class="btn btn-primary" >Add</button>
                            </form>
                        </div>
                        <div class="modal-footer">
                            <button type="button"  class="btn btn-default" v-on:click="clearStudent" data-dismiss="modal">Close</button>
                        </div>
                    </div>
                </div>
            </div>
            <div id="myModalu" class="modal fade" role="dialog">
                <div class="modal-dialog">
                    
                    <div class="modal-content">
                        <div class="modal-header">
                            <button type="button" class="close" data-dismiss="modal">×</button>
                            <h4 class="modal-title">Update students</h4>
                        </div>
                        <div class="modal-body">
                            <form action="" method="POST" role="form" v-on:submit.prevent="updateStudent">
                                <div class="form-group">
                                    <label for="">Name</label>
                                    <input type="text" class="form-control" v-model="student.name" required="" id="" placeholder="Name...">
                                </div>
                                <div class="form-group">
                                    <label for="">Age</label>
                                    <input type="number" class="form-control" v-model="student.age" id="" required="" placeholder="Age...">
                                </div>
                                <div class="form-group">
                                    <label for="">Class</label>
                                    <input type="text" class="form-control"  v-model="student.class" required="" id="" placeholder="Class...">
                                </div>
                                <button type="submit"  class="btn btn-primary" >Update</button>
                            </form>
                        </div>
                        <div class="modal-footer">
                            <button type="button"  class="btn btn-default" v-on:click="clearStudent" data-dismiss="modal">Close</button>
                        </div>
                    </div>
                </div>
            </div>
        </div>
        <script src="https://unpkg.com/vue"></script>
        <script>
            var vue = new Vue({
                el: '#app-demo',
                data: {
                    search: '',
                    student: {
                        id: 0,
                        name: '',
                        age: '',
                        class: ''
                    },
                    people: [{
                        name: 'Vu Van A',
                        age: '20',
                        class: '12B'
                    }, {
                        name: 'Vu Van B',
                        age: '12',
                        class: '12A'
                    }, {
                        name: 'Vu Van C',
                        age: '14',
                        class: '12E'
                    }, {
                        name: 'Vu Van D',
                        age: '18',
                        class: '12D'
                    }, ],
                },
                methods: {
                    addStudent: function() {
                        if (this.people.push(this.student)) {

}
                    },
                    clearStudent: function() {
                        this.student = {
                            id: '',
                            name: '',
                            age: '',
                            class: ''
                        };
                    },
                    deleteStudent: function(index) {
                        delete this.people.splice(index,1);
                    },
                    updateStudent: function (index) {
                        this.student = this.people[index];
                        this.student.id = index;
                    },
                },
                computed: {
                    searchs: function (newsearch) {
                        var da = [];
                        var search = this.search;
                        if (this.search != '') {
                            this.people.forEach(function (item,index) {

if (item.name.toLowerCase().indexOf(search.toLowerCase()) > -1 ) {
                                    console.log(item.name.toLowerCase());
                                    da.push(item);
                                }
                            });
                            return da;
                        } else {
                            return this.people;
                        }
                    }
                }
            });
            vue.people.push({
                name: 'Vu Van E',
                age: '22',
                class: '12G'
            });
        </script>
    </body>

</html>