Installing Node.js & Express

1. Install Node.js

Before using Express, you need to install Node.js.

• Download & Install

  • Go to Node.js official website and download the LTS version.
  • Follow the installation instructions for your OS.
  • Verify installation by running:

    node -v
    npm -v
    

• Using a Package Manager (Linux/macOS)

  • Install via Homebrew (macOS):

    brew install node
    

  • Install via APT (Ubuntu/Debian):

    sudo apt update
    sudo apt install nodejs npm
    

• Using Node Version Manager (Recommended)

  • Install nvm:

    curl -fsSL https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.4/install.sh | bash
    

  • Install and use Node.js:

    nvm install --lts
    nvm use --lts
    

2. Initialize a Node.js Project

Create a new project and navigate to its directory:

mkdir my-express-app
cd my-express-app
npm init -y  # Creates package.json

3. Install Express

Install Express as a dependency:

npm install express

To install it globally (not recommended for projects):

npm install -g express

4. Verify Installation

Create a simple server in index.js:

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

app.get('/', (req, res) => {
    res.send('Hello, Express!');
});

app.listen(3000, () => {
    console.log('Server running on http://localhost:3000');
});

Run the server:

node index.js

Visit http://localhost:3000/ in your browser to confirm it works.