http.createServer(app)与app()的区别

第一种写法：

var express = require(‘express’);

var app = express(); 

app.listen(3000);

第二种写法：

var express = require(‘express’);

var http = require(‘http’);

var app = express();

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

区别：

app就是一个:

function (req, res) {}

同时具备一个属性:

app.listen = function (port) {
  http.createServer(this).listen(port);
};

转载于:https://www.cnblogs.com/dabinglian/p/6874290.html