1 watch（侦听一个或多个响应式数据源，并在数据源变化时调用所给的回调函数。比如ref或reactive声明的变量）

 import {watch,reactive} from "vue";const state = {name:1}watch(state.name,(newValue,OldValue) => {console.log(newValue);console.log(OldValue);})2 watchEffect