没有用reactive包裹的非响应式数据，为什么也具有响应式

老师你好，没有用reactive包裹的非响应式数据，为什么也具有响应式，我点击按钮修改数据 ，页面也会跟着改变。

<template>

  <div class="wrapper">

    <div class="data" v-for="item in state.todoList" :key="item">state:{{item}}</div>

    <div class="data" v-for="item in objdata.objlist" :key="item">objdata:{{item}}</div>

    <el-button @click="handleClick">change</el-button>

  </div>

</template>

<script>

import {reactive} from 'vue'

export default {

    name:'TestResponse',

    setup(){

      const state = reactive({

        todoList:['打牌','game','test']

      })

      const objdata = {

        objlist:['obj','dfe']

      }

      const handleClick = () => {

        state.todoList.push('music')

        objdata.objlist.push('kkk')

      }

      return {state,objdata,handleClick}

    }

}

</script>