Working with Streams in Node.js

1. Introduction

Streams are a powerful feature in Node.js that allow you to work with data in a more efficient manner. They provide a way to handle reading and writing data in a continuous manner, rather than loading everything into memory at once.

2. Types of Streams

Node.js has four types of streams:

• Readable: Streams from which data can be read.
• Writable: Streams to which data can be written.
• Duplex: Streams that are both readable and writable.
• Transform: A type of duplex stream that modifies the data as it's written and read.

3. Creating Streams

To create streams, you can use the built-in stream module.

const { Readable, Writable } = require('stream');

const readableStream = new Readable({
    read() {}
});

const writableStream = new Writable({
    write(chunk, encoding, callback) {
        console.log(chunk.toString());
        callback();
    }
});

4. Reading from Streams

Reading from streams can be done using the on method to listen for data events.

readableStream.on('data', (chunk) => {
    console.log(`Received ${chunk.length} bytes of data.`);
});

5. Writing to Streams

You can write to a writable stream using the write method.

writableStream.write('Hello, World!');
writableStream.write('Another message.');

6. Piping Streams

Piping allows you to connect a readable stream to a writable stream. Here's how to do it:

const fs = require('fs');

const readStream = fs.createReadStream('input.txt');
const writeStream = fs.createWriteStream('output.txt');

readStream.pipe(writeStream);

7. Best Practices

When working with streams, keep these best practices in mind:

• Always handle errors by listening for the error event.
• Use pipe for efficient data transfer between streams.
• Close streams properly to free up resources.

8. FAQ