SOURCE

var vm = new Vue({
  el: '#app',
  data: {
    childrens: {
      name: '小强',
      age: 20,
      sex: '男'
    },
    tdArray: ["1", "2"],
    lastName: "张三"
  },
  watch: {
    childrens: {
      handler: function(val, oldval) {
        console.log(val.name)
      },
      deep: true //对象内部的属性监听，也叫深度监听  
    },
    'childrens.name': function(val, oldval) {
      console.log(val + "aaa")
    },
    //键路径必须加上引号  
    lastName: function(val, oldval) {
      console.log(this.lastName)
    }
  },
  //以V-model绑定数据时使用的数据变化监测  
});
vm.$watch("lastName", function(val, oldval) {
  console.log(val)
}) //主动调用$watch方法来进行数据监测</span>  

<div id="app">
  <input type="text" v-model:value="childrens.name" />
  <input type="text" v-model:value="lastName" />
</div>