Node.js basics

If you have some basic knowledge about Node.js, you can skip this chapter or just regard it as a reference.

Node.js version "Hello World"

console.log('Hello World');

• Run the script on your terminal

node test.js

Version management of Node.js

With the effort of worlds's contributors, Node.js is getting better and better. So it is a usual for us to change and update the version of Node.js on our machine.

I recommend NVM to do this stuff. Its features are complete and convinent. For more infomation, you could visit its Github page.

Module system

Node.js implement the CommonJS sepc):

• Use global to define a global variable:

global.test = true;

• Use require to import a module:

var fs = require('fs');

• Use module.exports to exports a module:

module.exports = function () {
    console.log('Hello Node.js');
};

• Use exports to export multiple methods or Object:

exports.foo = function () {};
exports.bar = function () {};

The simplest Node.js server:

var http = require('http');

http.createServer(function (req, res) {
    res.send('Hello');
    res.end();
}).listen(3000);

Visit it on localhost:300 and you could see the word "Hello".