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