Hands on With Node.js - Preface - Node.js Example

'use strict'

// Example 1
// output hello, then two seconds later output world
setTimeout(function () {
	console.log('world')
}, 2000)
console.log('hello')

// Example 2
require('fs').readFile('one.txt', function (err, data) {
	if (err) throw err
	console.log('contents:', data.toString())
})

// Example 3
require('fs').readFile('one.txt', function (err, data) {
	if (err) throw err
	console.log('one:', data.toString())
})
require('fs').readFile('two.txt', function (err, data) {
	if (err) throw err
	console.log('two:', data.toString())
})

// Example 4
// start a server
const server = require('http').createServer(function (req, res) {
    console.log('request received')
	res.writeHead(200, { 'Content-Type': 'text/plain' })
	res.end('Hello World\n')
}).listen({port: 8000, host: '127.0.0.1'}, _ => console.log('server listening'))
// close the server after 10 seconds
setTimeout(function () {
    server.close(_ => console.log('server closed'))
}, 10 * 1000)