关于前端:记录vue30的坑watch新旧数据相同

1.先上代码

<script>import { reactive ,toRefs, ref ,watch} from "vue";import { useRouter } from "vue-router";export default {  setup() {    const state = reactive({      password: null,      username: null,    });    // const router = useRouter();    // const goto_home = (() => {    //   router.replace( '/userList')    // })    const affirm = ()=>{      console.log('enter')    }    watch(()=>state.username, (newValue, oldValue) => { //间接监听    console.log("扭转了",newValue,oldValue,state);});    return {      affirm,      ...toRefs(state)    };  },};</script>

这是正确的监听形式

2.如果是监听全副时

    watch(state, (newValue, oldValue) => { //间接监听    console.log("count扭转了",newValue,oldValue,state);});

newValue和 oldValue是一样的（都是批改后的值）

举荐形式1，这样能够监听到批改前和批改后的值