watch怎么深度监听对象变化

Answer 1

deep设置为true 就可以监听到对象的变化

    let vm=new Vue({
        el:"#first",
        data:{msg:{name:'北京'}},
        watch:{

            msg:{
                handler (newMsg,oldMsg){
                    console.log(newMsg);
                },
                immediate:true,
                deep:true
            }
        }
    })