SOURCE

 var app= new Vue({
        el:"#app",
        data:{
            arryTst:['a','b','c'],
            person:[
                {name:"Lee", age:21, sex:"boy"},
                {name: "Ng", age:21, sex:"girl"},
                {name:"Wong", age:21, sex:"boy"}
                ]
        },

         methods:{
            addItem:function(){
                this.arryTst.push(
                    "d"
                )
            }
         },

        watch:{

        },

        computed:{

        }

 })

<script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
<div id="app">
    <ul>
 
        <li v-for="item in person">
            <div v-for='(value, key, index) in item'>{{index}}.{{key}}:{{value}}</div>
        </li>
    </ul>
    {{arryTst}}
    <input type="button" value="Add Item" @click="addItem"></input>
</div>