SOURCE

var app = new Vue({
  el: '#app',
  data() {
    return {
      myArray: [{id:1, name: 'aa'}],
      myArray2: [],
      show: true
    }
  }, 
  methods: {

  }
});

<div id="app">
 <button @click="show = !show">
    Toggle render
</button>
<transition name="fade" :appear = 'true'>
    <p v-if="show">hello</p>
  </transition>
</div>

.fade-enter-active, .fade-leave-active {
  transition: opacity .5s;
}
.fade-enter, .fade-leave-to /* .fade-leave-active below version 2.1.8 */ {
  opacity: 0;
}