Node.js Server >>> Express

Node.js？

• JavaScript 執行環境(run-time environment)
• 讓 JavaScript 從瀏覽器解放

Node.js server

回傳 HTML >>> Content-Type >>> text/html

// include http module from Node.js
const http = require('http');

// define server related variables
const hostname = 'localhost';
const port = 3000;

const server = http.createServer((req, res) => {
  // HTTP status code
  res.statusCode = 200;
  // HTTP response Headers >>> content-type
  res.setHeader('Content-Type', 'text/plain');
  // HTTP response Body
  res.end('This is my first server created in Node.js');
});

// start and listen the server
server.listen(port, hostname, () => {
  console.log(`The server is listening on http://${hostname}:${port}`);
});

Express

• JavaScript 後端框架

安裝方式

• npm init / npm init -y
• npm i express

const express = require('express');
const app = express();
const port = 3000;

app.get('/', (req, res) => {
  res.send('This is my first Express.js app');
});
app.listen(port, () => {
  console.log(`Express is running on http://localhost:${port}`);
});