express 创建server

var express = require('express');
var app = express();
app.listen(3000);

var express = require('express');
var https = require('https');
var http = require('http');
var app = express();

http.createServer(app).listen(80);

请问这两种创建server的方式有什么区别？

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http://stackoverflow.com/questions/17696801/express-js-app-listen-vs-server-listen
这里有，善用搜索

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/*
 * 创建服务器两种写法，第一种写法:
*/
var server = http.createServer(function(req,res)
{
    //这里的req为http.serverRequest
    res.writeHeader(200,{'Content-Type':'text/plain'});
    res.end('hello world');
});


/*
 * 创建服务器的第二种写法:
 */
var server = new http.Server();
server.on('request',function(req,res){
    res.writeHeader(200,{'Content-Type':'text/plain'});
    res.end('hello world');
});