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Describe the `Buffer` class in Node.js and its use cases.

Q: Describe the `Buffer` class in Node.js and its use cases.

**TL;DR.** A Buffer is a fixed-length chunk of **raw binary data** outside V8's heap — Node's way to handle bytes (files, network packets, crypto) before strings existed for binary. It's a subclass of Uint8Array , so it works with typed-array APIs, and you decode/encode it with a specified character encoding. Buffer (raw bytes) 48 65 6c 6c 6f toString('utf8') "Hello"<

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This question assesses knowledge of how Node.js handles binary data, which is essential for low-level operations.

bufferbinary datastreamsperformance

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Encode, decode, and concat

const buf = Buffer.from('Hello', 'utf8');
console.log(buf);                 // <Buffer 48 65 6c 6c 6f>
console.log(buf.toString('hex')); // 48656c6c6f
console.log(buf.toString('base64'));

// Collect stream chunks then decode once:
const parts = [];
stream.on('data', (c) => parts.push(c));
stream.on('end', () => console.log(Buffer.concat(parts).toString('utf8')));

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