SOURCE

var vm=new Vue({
   el:'#vue',
   data:{
       msg:'hello world',
       list:['apple','banana','orange'],
       fname:''
   },
   methods:{
       add:function(){
           this.list.push(this.fname);
       },
       del:function(){
        this.list.pop();
       }
   }
}); 
Vue.set(vm.list,'1','xhr');
vm.$set(vm.list,'2','showtime');

<div id="vue">
	<ul>
    <li :key='index' v-for='(item,index) in list'>{{item}}</li>
	</ul>
    <input type="text" v-model='fname'>
    <button v-on:click='add'>submit</button>
    <button @click='del'>delete</button>
</div>

ul li{
    list-style:none;
}