Node.js

Node.js

Node.js là JavaScript runtime được xây dựng trên V8 engine, cho phép chạy JavaScript trên server.

Basic Server

const http = require("http");

const server = http.createServer((req, res) => {
  res.writeHead(200, { "Content-Type": "text/plain" });
  res.end("Hello World!");
});

server.listen(3000, () => {
  console.log("Server running on port 3000");
});

Modules

// ES Modules
import express from "express";
import { readFile } from "fs/promises";

// CommonJS
const express = require("express");
const fs = require("fs");

File System

import { readFile, writeFile } from "fs/promises";

// Read file
const data = await readFile("file.txt", "utf-8");

// Write file
await writeFile("output.txt", "Hello World!");

Environment Variables

.env

PORT=3000
DATABASE_URL=postgresql://...

// app.js
import 'dotenv/config';

const port = process.env.PORT || 3000;

Learn More

• 👉 Express.js
• 📚 Middleware