vue2实现原理

使用Object.defineProperty()的get()与set()来实现响应式

<script>let p = {}let person = {name: "张三",sex:"男",hobby: ["吃饭","睡觉"]}Object.defineProperty(p,"age",{// value: 18,// enumerable: true, //是否可以遍历,默认 false// writable: true,  //是否可以修改,默认 falseconfigurable: true, //是否可以被删除,默认 falseget(){console.log("有人读取了age属性")return p.age;},set(value){console.log("有人修改了age属性")p.age = value}})
</script>

Vue2响应式存在的问题

1. 对象增加属性

this.$set(this.perosn,'age',30)
Vue.set(this.person,"age",30)

2. 删除对象属性

this.$delete(this.perosn,'age')
Vue.delete(this.person,"age")

3. 修改数组

this.$set(this.person.hobby,0,"学习")
Vue.set(this.person.hobby,0,"学习")
this.person.hobby.splice(0,1,"学习")