node-服务器

原生：

 const http=require('http');
 http.createServer((request,response)=>{
   response.writeHead(200,{"Content-Type": "text/plain"});
   response.write("Hello World");
   response.end();
 }).listen(8888)

 const http=require('http');
 function onRequest(req,res){
   res.writeHead(200,{"Content-Type":"text/plain"});
   res.write('Hello World');
   res.end();
 }
 http.createServer(onRequest).listen(8888);

koa:

 const Koa=require('koa');
 const app=new Koa();
 app.listen(8888)

express

 const express=require('express');
 const http=require('http');
 const app=express();
 const server=http.createServer(app);
 server.listen(8081);