Node.js Get Started

Node.js Get Started: Environment Setup & Script Execution

Getting started with Node.js involves installing the runtime, initializing standard configuration files, and creating executable JavaScript scripts that run natively outside browser contexts.

Developer Setup & Project Initialization Workflow

flowchart LR
    A["Install Node.js (via NVM)"] --> B["Initialize Project (npm init -y)"]
    B --> C["Configure package.json ('type': 'module')"]
    C --> D["Write App Script (app.js)"]
    D --> E["Run via CLI (node app.js)"]

Setting Up a Modern Project

To configure ES Modules support, set "type": "module" in your package.json:

{
  "name": "my-node-app",
  "version": "1.0.0",
  "type": "module",
  "scripts": {
    "start": "node index.js",
    "dev": "node --watch index.js"
  }
}

Practical Code Example

// index.js - Hello World CLI & Environment Verification
import { osInfo } from './utils.js';

function main() {
    console.log('--- Node.js Runtime Initialized ---');
    console.log(`Current Working Directory: ${process.cwd()}`);
    console.log(`Process ID (PID): ${process.pid}`);
    console.log(`System Memory: ${osInfo()}`);
}

main();

// utils.js
import os from 'node:os';

export function osInfo() {
    const totalMem = (os.totalmem() / (1024 * 1024 * 1024)).toFixed(2);
    return `${os.type()} ${os.arch()} with ${totalMem} GB RAM`;
}

Best Practices & Gotchas

• Use NVM (Node Version Manager): Manage multiple installed Node.js versions per project instead of relying on global system-level binary installs.
• Leverage Built-In Watch Mode: Use node --watch index.js in Node.js 18+ for automatic script reloads without needing third-party packages like nodemon.
• Commit .nvmrc: Save target Node version inside .nvmrc (e.g. 20.11.0) so all team members run identical Node.js versions.

Self-Check Challenge

Create a script server.js and add an npm script entry "dev" in package.json that uses node --watch server.js to execute it!