我尝试写了以下代码，watch的函数pre 和 cur的值打印都一样的。

        const app = Vue.createApp({
            setup(props, context) {
                const {reactive, watch} = Vue

                let nameObj = reactive({name:'', engName:''})

                watch(nameObj, (curNameObj, preNameObj) => {
                    console.log(curNameObj,preNameObj) //这里两个打印都一样的 
                })

                return {
                    nameObj
                }
            },

            template: `
            <div >
                Name: <input v-model="nameObj.name"/>
                EngName :<input v-model="nameObj.engName" />
            </div>
            `,
        })