> For the complete documentation index, see [llms.txt](https://bryan-guner.gitbook.io/my-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://bryan-guner.gitbook.io/my-docs/redux/repos/examples/real-world/node_modules/buffer-from.md).

# Buffer From

A [ponyfill](https://ponyfill.com) for `Buffer.from`, uses native implementation if available.

## Installation

```
npm install --save buffer-from
```

## Usage

```js
const bufferFrom = require('buffer-from')

console.log(bufferFrom([1, 2, 3, 4]))
//=> <Buffer 01 02 03 04>

const arr = new Uint8Array([1, 2, 3, 4])
console.log(bufferFrom(arr.buffer, 1, 2))
//=> <Buffer 02 03>

console.log(bufferFrom('test', 'utf8'))
//=> <Buffer 74 65 73 74>

const buf = bufferFrom('test')
console.log(bufferFrom(buf))
//=> <Buffer 74 65 73 74>
```

## API

### bufferFrom(array)

* `array` \<Array>

Allocates a new `Buffer` using an `array` of octets.

### bufferFrom(arrayBuffer\[, byteOffset\[, length]])

* `arrayBuffer` \<ArrayBuffer> The `.buffer` property of a TypedArray or ArrayBuffer
* `byteOffset` \<Integer> Where to start copying from `arrayBuffer`. **Default:** `0`
* `length` \<Integer> How many bytes to copy from `arrayBuffer`. **Default:** `arrayBuffer.length - byteOffset`

When passed a reference to the `.buffer` property of a TypedArray instance, the newly created `Buffer` will share the same allocated memory as the TypedArray.

The optional `byteOffset` and `length` arguments specify a memory range within the `arrayBuffer` that will be shared by the `Buffer`.

### bufferFrom(buffer)

* `buffer` \<Buffer> An existing `Buffer` to copy data from

Copies the passed `buffer` data onto a new `Buffer` instance.

### bufferFrom(string\[, encoding])

* `string` \<String> A string to encode.
* `encoding` \<String> The encoding of `string`. **Default:** `'utf8'`

Creates a new `Buffer` containing the given JavaScript string `string`. If provided, the `encoding` parameter identifies the character encoding of `string`.

## See also

* [buffer-alloc](https://github.com/LinusU/buffer-alloc) A ponyfill for `Buffer.alloc`
* [buffer-alloc-unsafe](https://github.com/LinusU/buffer-alloc-unsafe) A ponyfill for `Buffer.allocUnsafe`