- expressjs.com – Installing
- npmjs.com – express
สร้างโฟลเดอร์ให้แอพชื่อ myapp
mkdir myapp cd myapp
ใช้คำสั่ง npm init เพื่อสร้างไฟล์ package.json
> npm init This utility will walk you through creating a package.json file. It only covers the most common items, and tries to guess sensible defaults. See `npm help init` for definitive documentation on these fields and exactly what they do. Use `npm install <pkg>` afterwards to install a package and save it as a dependency in the package.json file. Press ^C at any time to quit. package name: (myapp) version: (1.0.0) description: entry point: (index.js) test command: git repository: keywords: author: license: (ISC) About to write to D:\Project\node\myapp\package.json: { "name": "myapp", "version": "1.0.0", "description": "", "main": "index.js", "scripts": { "test": "echo \"Error: no test specified\" && exit 1" }, "author": "", "license": "ISC" } Is this OK? (yes) y
จะได้ไฟล์ package.json
{ "name": "myapp", "version": "1.0.0", "description": "", "main": "index.js", "scripts": { "test": "echo \"Error: no test specified\" && exit 1" }, "author": "", "license": "ISC" }
ติดตั้ง express ให้กับโปรเจ็กส์นี้
npm install express --save
ไฟล์ package.json จะเพิ่ม dependencies
{ "name": "myapp", "version": "1.0.0", "description": "", "main": "index.js", "scripts": { "test": "echo \"Error: no test specified\" && exit 1" }, "author": "", "license": "ISC", "dependencies": { "express": "^4.17.1" } }
สร้างไฟล์ server.js
var express = require('express') var app = express() app.get('/', function (req, res) { res.send('Hello World') }) app.listen(3000) console.log("Server running at port 3000");
หรือ
const express = require('express') const app = express() const port = 3000 app.get('/', (req, res) => res.send('Hello World!')) app.listen(port, () => console.log(`App listening on port ${port}!`))
ทดลองรัน
> node server.js Server running at port 3000
เปิด browser ไปที่ http://localhost:3000/
จะเห็นข้อความ Hello World