Detailed explanation of responsive tool functions in Vue3: Convenient management of responsive data

The responsive tool functions introduced in Vue 3 greatly facilitate our management and operation of responsive data. In Vue 2, we need to use Object.defineProperty() to manually set getters and setters, but in Vue 3, we can use simpler and easier-to-understand functions to achieve the same effect. This article will introduce in detail the reactive tool functions in Vue 3 and how to use them.

1. Reactive function

The Reactive function is the most basic responsive tool function in Vue 3. It receives a normal object and returns a reactive proxy object through which we can access and update the property values ​​of the proxied object.

Usage:

import { reactive } from 'vue'

const obj = reactive({
  name: '张三',
  age: 26,
  job: '前端开发工程师'
})

console.log(obj.name) // 输出：张三

obj.name = '李四' // 修改值

console.log(obj.name) // 输出：李四

2. Ref function

The Ref function is another commonly used responsive tool function in Vue 3. It takes a parameter and returns a reactive reference object, which can be accessed and modified. An important use of the Ref function is to use responsive data in templates.

Usage:

import { ref } from 'vue'

const count = ref(0)

console.log(count.value) // 输出：0

count.value++ // 修改值

console.log(count.value) // 输出：1

3. Computed function

The Computed function is a responsive tool function in Vue 3 for calculating derived data. It receives two parameters, the first is the getter function of the calculated attribute, and the second is the reactive data that the getter depends on.

Usage:

import { reactive, computed } from 'vue'

const obj = reactive({
  name: '张三',
  age: 26,
  job: '前端开发工程师'
})

const message = computed(() => {
  return `我叫${obj.name}，今年${obj.age}岁，是个${obj.job}`
})

console.log(message.value) // 输出：我叫张三，今年26岁，是个前端开发工程师

4. Watch function

The Watch function is a responsive tool function in Vue 3 that is used to monitor responsive data changes. It receives two parameters, the first is the responsive data to be monitored, and the second is the callback function.

Usage:

import { reactive, watch } from 'vue'

const obj = reactive({
  name: '张三',
  age: 26,
  job: '前端开发工程师'
})

watch(
  () => obj.age,
  (newVal, oldVal) => {
    console.log(`年龄从${oldVal}岁变成了${newVal}岁`)
  }
)

obj.age = 27 // 输出：年龄从26岁变成了27岁

Summary

The reactive tool functions in Vue 3 greatly simplify the management and operation of reactive data, including Reactive, Ref, Computed and Watch etc. Use these functions to easily create responsive data and even use it in templates. Mastering the use of these functions can help us better use Vue 3 to develop responsive applications.

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