ES6 模块化

一、html

script 标签要声明 type = 'module' 

1 <script type="module">
2     import behaviors, { cat, dog } from "./animals";
3     console.log(behaviors, cat, dog);
4 </script>

二、animals.js

1 export default class behaviors {}
2 
3 export function cat() {}
4 
5 export { dog };
6 
7 function dog() {}

三、server.js

 1 const http = require("http"),
 2     fs = require("fs");
 3 
 4 const server = new http.Server();
 5 
 6 server.on("request", (req, res) => {
 7     const url = req.url;
 8     const suffix = url.match(/(?<=\.)\w*$/)?.[0] || "js"; // 匹配文件格式
 9     const fileName = url.match(/.*(?=\.\w*$)|\/?\w*/)[0]; // 匹配文件名
10     let mime = "";
11     switch (suffix) {
12         case "html":
13             mime = "text/html";
14             break;
15         case "ico":
16             mime = "image/x-icon";
17             break;
18         default:
19             mime = "text/javascript";
20     }
21 
22     fs.readFile(`.${fileName}.${suffix}`, (err, data) => {
23         res.writeHead(200, {
24             "Content-Type": mime,
25         });
26         res.write(data);
27         res.end();
28     });
29 });
30 
31 server.listen(80);

五、运行

node server.js

浏览器访问：http://localhost/behaviors.html

六、补充 export 与 import

1.   export default class behaviors {} 对应 import behaviors from "./animals"; 
2.  export function cat() {} 和 export { dog }; function dog() {} 对应 import { cat, dog } from "./animals"; 
3. 可以像上面的例子一样，混合使用