Apa iku Buffers ing Node.js?

Question

Accepted Answer

A **Buffer** adalah cara Node kanggo nangani **raw binary data** — sekuensi bait sing panjange tetep sing disimpen ing luar V8 heap. Merga string JavaScript kanggo teks (Unicode), Buffers ana kanggo nggarap binary: isi file, paket jaringan, gambar, enkripsi, etc.

## Kenapa Buffers ana

```text
JavaScript strings → text (UTF-16). Can't cleanly represent arbitrary bytes.
Buffers → raw bytes (0–255 each). For binary data that isn't text.
```

Yuwi sampeyan maca file utawa narima data jaringan, iku teka minangka bait — Buffer — sing banjur bisa sampeyan dekode dadi string yeneng iku teks, utawa diproses minangka binary yeneng ora.

## Nggawe lan nggunakake Buffers

```js
const buf = Buffer.from("Hello");          // from a string → bytes
const buf2 = Buffer.from([72, 105]);       // from byte values → "Hi"
const buf3 = Buffer.alloc(10);             // 10 zero-filled bytes

buf.length;          // 5 (bytes, not characters)
buf.toString("utf8"); // "Hello" — decode back to text
buf.toString("hex");  // "48656c6c6f"
buf.toString("base64"); // "SGVsbG8="
buf[0];              // 72 — access individual bytes
```

## Nang endi Buffers muncul

```js
// file reads without an encoding return a Buffer
const data = await fs.promises.readFile("image.png"); // Buffer (binary)
const text = await fs.promises.readFile("file.txt", "utf8"); // string (decoded)

// streams emit Buffer chunks
req.on("data", (chunk) => { /* chunk is a Buffer */ });

// crypto, compression, network protocols all work with Buffers
crypto.randomBytes(16); // a Buffer of 16 random bytes
```

Yeneng sampeyan maca file *tanpa* nentokaken encoding, sampeyan oleh Buffer; nentokaken `"utf8"` lan Node dekode dadi string kanggo sampeyan.

## Titik sing rada halus: bait vs karakter

```js
Buffer.from("café").length; // 5 (é is 2 bytes in UTF-8) — NOT 4 characters
```

Panjang Buffer ing **bait**, kang bisa beda saka jumlah karakter kanggo teks multi-bait (non-ASCII) — relevan yuwi irisan binary data.

## Kenapa iki penting

Buffers yaiku carane Node nangani kabeh **binary data**, kang ora bisa dihindari ing kerjaan server: maca file non-teks, ngproses streams, protokol jaringan, kriptografi, upload gambar/file, lan kompresi.

Paham bilih I/O dhasare kawinan ing bait (Buffers) — lan carane ngowah antarane Buffers lan string karo encoding kang bener — penting banget yuwi sampeyan lunga nang liyan teks polos, lan iku dadi dasar streams, file system, lan crypto.