Beginner LevelNode JS
What are the 4 fundamental types of Node.js Streams (Readable, Writable, Duplex, Transform)?
❓ Interview Prompt: Explain Streams data processing, memory efficiency, 4 stream types (Readable, Writable, Duplex, Transform), and piping.
Streams process data sequentially in chunks rather than buffering entire files into RAM at once:
1
Readable: Source stream data can be read from (e.g. 'fs.createReadStream()').
2
Writable: Destination stream data can be written to (e.g. 'fs.createWriteStream()').
3
Duplex: Stream that is both Readable and Writable (e.g. TCP Net socket).
4
Transform: Duplex stream that modifies or transforms data during write/read (e.g. 'zlib.createGzip()').
Code Implementation Example
javascript
import fs from 'node:fs';
import zlib from 'node:zlib';
// Stream copy file with Gzip compression: uses flat memory!
fs.createReadStream('input.txt')
.pipe(zlib.createGzip())
.pipe(fs.createWriteStream('input.txt.gz'))
.on('finish', () => console.log('File compressed via streams successfully!'));💡Compressing files using Readable, Transform, and Writable streams.
🎯 Interview Key Takeaway
Use Streams to process large datasets sequentially, keeping Node.js memory footprint flat.
#Streams#Readable#Writable#Transform#Beginner
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