vue3 composition 模式下watch object
记录一些watch 一个object，即有子成员
const message = ref('')const user = ref({firstName: '',lastName: ''})
对user 只能 watch value，直接watch user或者user.value.firstName都不可以。
watch(message, (newValue, oldValue) => {console.log('New Value', newValue)console.log('Old Value', oldValue)// changelog.value = changelog.value + newValue + '=》' + oldValue})watch(user.value,(newValue, oldValue) => {message.value = newValue.firstName + oldValue.lastNameconsole.log('user New Value')console.log('user Old Value')// changelog.value = changelog.value + newValue + '=》' + oldValue})
或者 使用callbacks
watch([// getter callbacks() => user.value.firstName,() => user.value.lastName],(newValues, oldValues) => {console.log('New First Name', newValues[0])console.log('Old First Name', oldValues[0])console.log('New Last Name', newValues[1])console.log('Old Last Name', oldValues[1])})