!DOCTYPE html html lang="en" head meta charset="UTF-8" meta name="viewport" content="width=device-width, initial-scale=1.0" meta http-equiv="X-UA-Compatible" content="ie=edge" titleDocument/title script src="./js/vue.js"/script /head body d
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>Document</title> <script src="./js/vue.js"></script> </head> <body> <div id="app"> <ul> <li v-for="item in arrayData">{{item}}</li> </ul> </div> <script> var vm = new Vue({ el: "#app", data: () => ({ arrayData: ["e1", "e2", "e3", "e4"] }) }) </script> </body> </html>
vue 下载到了本地 ，那么渲染页面用了多长时间呢？
利用谷歌performance 可以看到
总共用了38.1ms
而用原生的js 达到同样效果
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<div id="app">
<ul id="ul">
</ul>
</div>
<script>
var fragement = document.createDocumentFragment();
var arrayData = ["e1", "e2", "e3", "e4"];
for (var item in arrayData) {
var li = document.createElement(‘li‘);
li.innerText = arrayData[item];
fragement.appendChild(li);
}
document.getElementById(‘ul‘).appendChild(fragement);
</script>
</body>
</html>
用时多少呢？
仅仅只有 9.8ms 哦，
当然vue的优势在于mvvm的方式不能只通过这一项就说vue不好。
这个数据仅供参考
我们再来看下jquery
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<div id="app">
<ul id="ul">
</ul>
</div>
<script src="./js/jquery3.4.1.js"></script>
<script>
$(function () {
var arrayData = ["e1", "e2", "e3", "e4"];
var html = ""
arrayData.forEach((item) => {
html += "<li>" + item + "</li>"
});
$("#ul").append(html);
});
</script>
</body>
</html>
11.8ms 可以说和原生js 很接近了
主要来看下react
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
//为了公平将资源下载到了本地
<!--
<script src="http://img.558idc.com/uploadfile/allimg/210615/1953062S7-2.jpg"></script>
<script src="http://img.558idc.com/uploadfile/allimg/210615/19530A932-3.jpg"></script>
<script src="http://img.558idc.com/uploadfile/allimg/210615/1953063c7-4.jpg"></script>
-->
<script src="./js/react.16.8.6.js"></script>
<script src="./js/reactDom16.8.6.js"></script>
<!-- 生产环境中不建议使用 -->
<script src="./js/babel.min.js"></script>
</head>
<body>
<div id="example"></div>
<script type="text/babel">
var arrayData = ["e1", "e2", "e3", "e4"];
ReactDOM.render(
arrayData.map((item,key)=>{
return <li key={key}>{item}</li>
}),
document.getElementById(‘example‘)
);
</script>
</body>
</html>
164ms
比vue 的38ms几乎多了4倍！
结论：
单从网页引入的方式来看
耗费时间 是 react>vue>jquery>js 的