首先把这个库加载下来
npm install -g express
这样会安装它所有依赖包，这个非常恐怖。这个框架要依赖这么多外来的东西，如果有一个不与时俱进就会拖累整个框架的质量。
C:\windows\System32>npm install -g expressnpm http GET https://registry.npmjs.org/expressnpm http 304 https://registry.npmjs.org/expressnpm http GET https://registry.npmjs.org/commander/1.2.0npm http GET https://registry.npmjs.org/connect/2.8.5npm http GET https://registry.npmjs.org/range-parser/0.0.4npm http GET https://registry.npmjs.org/mkdirp/0.3.5npm http GET https://registry.npmjs.org/cookie/0.1.0npm http GET https://registry.npmjs.org/buffer-crc32/0.2.1npm http GET https://registry.npmjs.org/fresh/0.2.0npm http GET https://registry.npmjs.org/methods/0.0.1npm http GET https://registry.npmjs.org/send/0.1.4npm http GET https://registry.npmjs.org/cookie-signature/1.0.1npm http GET https://registry.npmjs.org/debugnpm http 304 https://registry.npmjs.org/cookie/0.1.0npm http 304 https://registry.npmjs.org/buffer-crc32/0.2.1npm http 304 https://registry.npmjs.org/fresh/0.2.0npm http 304 https://registry.npmjs.org/mkdirp/0.3.5npm http 304 https://registry.npmjs.org/methods/0.0.1npm WARN package.json methods@0.0.1 No repository field.npm WARN package.json methods@0.0.1 No readme data.npm http 304 https://registry.npmjs.org/cookie-signature/1.0.1npm WARN package.json cookie-signature@1.0.1 No repository field.npm http 304 https://registry.npmjs.org/debugnpm http 304 https://registry.npmjs.org/commander/1.2.0npm http 304 https://registry.npmjs.org/range-parser/0.0.4npm WARN package.json range-parser@0.0.4 No repository field.npm http 304 https://registry.npmjs.org/send/0.1.4npm http 304 https://registry.npmjs.org/connect/2.8.5npm http GET https://registry.npmjs.org/mimenpm http GET https://registry.npmjs.org/keypressnpm http GET https://registry.npmjs.org/formidable/1.0.14npm http GET https://registry.npmjs.org/bytes/0.2.0npm http GET https://registry.npmjs.org/qs/0.6.5npm http GET https://registry.npmjs.org/pause/0.0.1npm http GET https://registry.npmjs.org/uid2/0.0.2npm http 304 https://registry.npmjs.org/keypressnpm http 304 https://registry.npmjs.org/pause/0.0.1npm http 304 https://registry.npmjs.org/formidable/1.0.14npm WARN package.json pause@0.0.1 No repository field.npm http 304 https://registry.npmjs.org/qs/0.6.5npm http 304 https://registry.npmjs.org/uid2/0.0.2npm WARN package.json uid2@0.0.2 No repository field.npm WARN package.json uid2@0.0.2 No readme data.npm http 304 https://registry.npmjs.org/mimenpm http 304 https://registry.npmjs.org/bytes/0.2.0npm WARN package.json bytes@0.2.0 No repository field.C:\Users\正美\AppData\Roaming\npm\express -> C:\Users\正美\AppData\Roaming\npm\node_modules\express\bin\expressexpress@3.3.5 C:\Users\正美\AppData\Roaming\npm\node_modules\express├── methods@0.0.1├── range-parser@0.0.4├── cookie-signature@1.0.1├── fresh@0.2.0├── buffer-crc32@0.2.1├── cookie@0.1.0├── debug@0.7.2├── mkdirp@0.3.5├── commander@1.2.0 (keypress@0.1.0)├── send@0.1.4 (mime@1.2.11)└── connect@2.8.5 (uid2@0.0.2, pause@0.0.1, qs@0.6.5, bytes@0.2.0, formidable@1.0.14)
然后我们在控制台切换到E盘，输入如下命令，创建一个目录，进入到它里面
E:\>mkdir helloworldE:\>cd helloworld
里面创建一个json文件，里面记录我们要依赖的包，项目名，版本号什么的，然后通过npm安装
{ "name": "helloworld", "description": "hello world test app", "version": "0.0.1", "private": true, "dependencies": { "express": "3.x" }} 然后执行npm install命令，Express 3.x 和它的依赖就安装到你的 ./node_modules 目录里了
到这里，我们才开始写代码！创建一个名为app.js 或者 server.js的文件，叫什么看你个人喜好了。 引入express 然后使用代码 express()创建一个新的应用程序:
var express = require('express');var app = express(); 现在我们要处理HTTP请求，返回hello world字样给前端
var express = require('express');var app = express();app.get('/', function(req, res){ res.send('hello world');});app.listen(3000); 然后在控制台执行node app, 打开浏览器就看到hello world的字样了。
好了，我们继续前进。在当前目录建立一个index.html页面。此时，目录结构为：
node_modulesapp.jsindex.htmlpackage.json
页面内容如下，暂时不引入JS与CSS文件
index 高级大气国际化的express.js页面
by 司徒正美
app.js文件的内容改成：
var express = require('express');var app = express();app.get('/', function(req, res){ res.send('hello world');});app.listen(3000); 刷新浏览器，就能发现正确地输出页面。在stackoverflow这篇文章中，提到另外两个方法。一个要用register方法，但这是express2.x的方法，现在已经移除；一个要用到engine 方法，它是用来指定模板引擎，但express默认什么引擎也不加载，因此我暂时也放弃它。
最后我们看看如何引入静态资态。我们在当前目录建立一个public文件夹，里面放置style.css, test.js文件：
window.onload = function(){ var p = document.createElement("p"); p.innerHTML = "动态创建元素节点" document.body.appendChild(p)} h3{ background:violet; color:#fff;} 然后app.js文件加多一行，变成这样
var express = require('express');var app = express();app.use(express.static(__dirname + '/public'));app.get('/', function(req, res){ res.sendfile('index.html');});app.listen(3000); 然后index.html改成这样：
index 高级大气国际化的express.js页面
by 司徒正美
刷新页面，就能看到效果了！