fs-http-Methods

File System (fs) & HTTP Module Methods

December 27, 2022

 Node.js provides a wide variety of built-in methods for working with files, networking, data, and more. Below are some of the key methods and functionalities categorized by their core modules:

1. File System (fs) Module Methods

The fs module allows you to work with the file system on your machine.

  • fs.readFile(path, callback): Asynchronously reads the contents of a file.

        const fs = require('fs');
        fs.readFile('example.txt', 'utf8', (err, data) => {
            if (err) throw err;
            console.log(data);
        });

  • fs.writeFile(file, data, callback): Asynchronously writes data to a file.

        fs.writeFile('example.txt', 'Hello, World!', (err) => {
            if (err) throw err;
            console.log('File has been saved!');
        });

  • fs.appendFile(file, data, callback): Appends data to a file.

    fs.appendFile('example.txt', 'Data to append', (err) => {
        if (err) throw err;
        console.log('Data appended to file!');
    });

  • fs.unlink(path, callback): Deletes a file.

    fs.unlink('example.txt', (err) => {
        if (err) throw err;
        console.log('File deleted');
    });

2. HTTP Module Methods

The http module is used to create HTTP servers and handle HTTP requests and responses.

  • http.createServer(callback): Creates an HTTP server.

    const http = require('http');
    http.createServer((req, res) => {
        res.writeHead(200, { 'Content-Type': 'text/plain' });
        res.end('Hello, World!');
    }).listen(3000);

  • req.on(event, callback): Listens for an event on the request (like 'data', 'end').

    req.on('data', chunk => {
        console.log(`Received chunk: ${chunk}`);
    });

  • res.write(data): Writes a response body to the client.

    res.write('Hello, ');
    res.write('World!');
    res.end();

  • res.end(): Signals that the response has been completed.

    res.end('Response finished.');

Path Module Methods

The path module provides utilities for working with file and directory paths.

  • path.join([...paths]): Joins multiple path segments into one.

    const path = require('path');
    const joinedPath = path.join('/foo', 'bar', 'baz/asdf');
    console.log(joinedPath);  // Outputs: '/foo/bar/baz/asdf'