Node.js — Buffers

What are Buffers?

Buffers handle binary data directly.

Creating Buffers

// From string
const buf1 = Buffer.from('Hello');

// From array
const buf2 = Buffer.from([72, 101, 108, 108, 111]);

// Allocate
const buf3 = Buffer.alloc(10);

Buffer Methods

const buf = Buffer.from('Hello World');

buf.toString()          // 'Hello World'
buf.length              // 11
buf[0]                  // 72 (H)
buf.toString('base64')  // Base64 encoded
buf.toString('hex')     // Hex encoded

Manipulating Buffers

const buf = Buffer.alloc(5);
buf.write('Hello');

const buf2 = Buffer.concat([buf, Buffer.from(' World')]);
console.log(buf2.toString()); // 'Hello World'

Encoding Types

Encoding	Description
utf8	Default, UTF-8
ascii	ASCII
base64	Base64
hex	Hexadecimal
binary	Binary

Practical Example

// Convert string to Base64
const encoded = Buffer.from('Hello').toString('base64');

// Convert Base64 back
const decoded = Buffer.from(encoded, 'base64').toString();

Mini Practice

1. Create buffers from strings
2. Convert between encodings
3. Concatenate buffers
4. Read and write binary data

Up Next

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