Handling requests and responses

Handling requests and responses in Node.js typically involves using the built-in http module or a more feature-rich framework like Express.js. I'll explain both approaches.

1. Using the http Module

The http module is a core module in Node.js that allows you to create a server to handle HTTP requests and send responses.

Example:

const http = require('http');

// Create an HTTP server
const server = http.createServer((req, res) => {
    // Handle incoming requests and send responses

    // Log the request method and URL
    console.log(`Received ${req.method} request for: ${req.url}`);

    // Set the content type to text/html
    res.setHeader('Content-Type', 'text/html');

    // Send a response back to the client
    res.statusCode = 200; // Set status code
    res.end('<h1>Hello, World!</h1>'); // Send a response body
});

// Start the server on port 3000
server.listen(3000, () => {
    console.log('Server is running on http://localhost:3000');
});

Explanation:

• http.createServer(): Creates a new HTTP server.
• req: Represents the incoming request, containing details like the URL, HTTP method, headers, etc.
• res: Represents the outgoing response, allowing you to set headers, status codes, and send data back to the client.
• res.end(): Ends the response, and sends the data to the client.

2. Using Express.js

Express.js is a popular web framework for Node.js that simplifies handling requests and responses.

Installation:

First, you need to install Express.js using npm:

npm install express

Example:

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

// Handle GET request to the root URL
app.get('/', (req, res) => {
    // Log the request method and URL
    console.log(`Received ${req.method} request for: ${req.url}`);

    // Send a response back to the client
    res.status(200).send('<h1>Hello, World with Express!</h1>');
});

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

Explanation:

• app.get(): Handles GET requests to the specified path ('/' in this case).
• req: The request object, similar to the one in the http module.
• res: The response object, with convenient methods like res.send() to send data to the client.
• app.listen(): Starts the server and listens on the specified port.

Key Differences:

• http module: More manual control, but requires more code to handle common tasks like routing, parsing request bodies, etc.
• Express.js: Provides a higher-level abstraction, making it easier to build web applications with less boilerplate code.

Which method do you prefer, or would you like more details on a specific aspect?