SOURCE

var app = new Vue({
  el: '#app',
  data() {
    return {
      myArray: [{id:1, name: 'aa'},{id:2, name: 'bb'},{id:3, name: 'cc'}],
      myArray2: []
    }
  }, 
  methods: {
      test() {
          
      }
  },
  created() {
      setTimeout(() => {
          this.myArray[2].name = 'hello'
      },1000)
  }
});

<div id="app">
    <div v-for="element in myArray" :key="element.id">{{element.name}}</div>
</div>