Vue 计算属性set和get

<template>
  <div class="hello">
    测试1：<input type="text" v-model="demoData1">
    测试2：<input type="text" v-model="demoData2">
    测试3：<input type="text" v-model="demoData3">
  </div>
</template>

<script>
export default {
  name: 'HelloWorld',
  computed: {
    demoData3: {
      get: function () {
        console.log('111')
        return this.demoData1
      },
      set: function (val) {
        console.log('222')
        this.demoData1 = val
      }
    }
  },
  data () {
    return {
      demoData1: '',
      demoData2: ''
    }
  }
}
</script>

改变demoData3：

改变demoData1：