关于原型

爱学习的前端歌谣

发布于 2023-10-18 11:12:39

1110

发布于 2023-10-18 11:12:39

文章被收录于专栏：前端小歌谣前端小歌谣

前言

我是歌谣最好的种树是十年前其次是现在今天继续给大家带来的是原型的讲解

环境配置

npm init -y

yarn add vite -D

修改page.json配置端口

{
  "name": "demo1",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "dev": "vite --port 3002"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "vite": "^4.4.9"
  }
}

声明方式

const obj={}


function Obj1(){}


const obj1=new Obj1()


const obj2=Object.create(null)


const obj3=new Object()


console.log(obj,obj1,obj2,obj3)

运行结果

原型案例

function Test(){
    this.a=1;
    this.b=2;
}
Test.prototype.c=3
Test.prototype.d=4
Object.prototype.e=5
Object.prototype.f=6
const test=new Test()
console.log(test)

运行结果

原型案例

function test(){}
console.dir(test.__proto__===Function.prototype)
console.log(Function.__proto__===Function.prototype)
function Test1(){
    this.a=1
}
Test1.prototype.b=2
const test1=new Test1()
//test.__proto__
const testPrototype=Object.getPrototypeOf(test1)
console.log(testPrototype===test1.__proto__)
const obj={
    a:1
}
Object.setPrototypeOf(obj,{
    b:1
})
console.log(obj)

运行结果

对象参数属性

const obj=Object.create({
    a:1,
    b:2
},{
    a:{
        value:3,
        writable:false,
        configurable:true,
        enumerable:true
    }
})
console.log(obj)

监听状态改变

index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <h1>


    </h1>
    <h2></h2>
    <p></p>
    <span></span>
    <script type="module" src="./index5.js"></script>
</body>
</html>

index5.js

import { useReacttive, useWatcher } from "./Delfin.js"
const state = useReacttive({
    title: `This is title`,
    content: `This is content`
})
function render() {
    document.querySelector("h1").innerText = state.title
    document.querySelector("h2").innerText = state.title
    document.querySelector("p").innerText = state.content
    document.querySelector("span").innerText = state.content
}
render()
useWatcher([
    document.querySelector('h1'), document.querySelector('h2')
],'title',(prev,cur)=>{
    console.log(prev,cur)
})
useWatcher([
    document.querySelector('p'), document.querySelector('span')
],'content',(prev,cur)=>{
    console.log(prev,cur)
})
setTimeout(()=>{
    state.title="这是标题",
    state.content="这是内容"
},1000)

delfin.js

import WatcherMap from "./WacthMap"
import Watcher from './Watcher'


const watcherMap=new WatcherMap()
export function useReacttive(state){
   return new Proxy(state,{
    get(target,key){
        return Reflect.get(target,key)
    },
    set(target,key,value){
        watcherMap[key].update(target[key],value)
        return Reflect.set(target,key,value)
    }
   })
}


export function useWatcher(collection,dep,callback){
   const watcher=new Watcher()
   watcher.set(collection,callback)
   watcherMap.set(dep,watcher)
}

WatchMap.js

export default function WactherMap(){


}


WactherMap.prototype.set=function(dep,watcher){
    this[dep]=watcher;
}

Wacther.js

export default function Watcher(){
   this.collection=[];
   this.cb=null
}
Watcher.prototype.set=function(collection,callback){
   this.collection=collection
   this.cb=callback
}
Watcher.prototype.update=function(prevValue,currentValue){
  this.collection.forEach(el=>{
    el.innerText=currentValue
  })
  this.cb[prevValue,currentValue]
}

运行结果