mirror of
https://github.com/nodejs/node.git
synced 2025-05-02 03:31:35 +00:00
6afd3fcf65
Some core modules can be loaded with or without the `node:` prefix. Using the prefix disambiguates which specifiers refer to core modules. This commit updates the docs to use the prefix everywhere a core module is referenced. PR-URL: https://github.com/nodejs/node/pull/42752 Fixes: https://github.com/nodejs/node/issues/38343 Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: Mestery <mestery@protonmail.com> Reviewed-By: Darshan Sen <raisinten@gmail.com> Reviewed-By: Akhil Marsonya <akhil.marsonya27@gmail.com> Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com> Reviewed-By: Mohammed Keyvanzadeh <mohammadkeyvanzade94@gmail.com> Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com> Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>
99 lines
3.0 KiB
Markdown
99 lines
3.0 KiB
Markdown
# String decoder
|
|
|
|
<!--introduced_in=v0.10.0-->
|
|
|
|
> Stability: 2 - Stable
|
|
|
|
<!-- source_link=lib/string_decoder.js -->
|
|
|
|
The `node:string_decoder` module provides an API for decoding `Buffer` objects
|
|
into strings in a manner that preserves encoded multi-byte UTF-8 and UTF-16
|
|
characters. It can be accessed using:
|
|
|
|
```js
|
|
const { StringDecoder } = require('node:string_decoder');
|
|
```
|
|
|
|
The following example shows the basic use of the `StringDecoder` class.
|
|
|
|
```js
|
|
const { StringDecoder } = require('node:string_decoder');
|
|
const decoder = new StringDecoder('utf8');
|
|
|
|
const cent = Buffer.from([0xC2, 0xA2]);
|
|
console.log(decoder.write(cent));
|
|
|
|
const euro = Buffer.from([0xE2, 0x82, 0xAC]);
|
|
console.log(decoder.write(euro));
|
|
```
|
|
|
|
When a `Buffer` instance is written to the `StringDecoder` instance, an
|
|
internal buffer is used to ensure that the decoded string does not contain
|
|
any incomplete multibyte characters. These are held in the buffer until the
|
|
next call to `stringDecoder.write()` or until `stringDecoder.end()` is called.
|
|
|
|
In the following example, the three UTF-8 encoded bytes of the European Euro
|
|
symbol (`€`) are written over three separate operations:
|
|
|
|
```js
|
|
const { StringDecoder } = require('node:string_decoder');
|
|
const decoder = new StringDecoder('utf8');
|
|
|
|
decoder.write(Buffer.from([0xE2]));
|
|
decoder.write(Buffer.from([0x82]));
|
|
console.log(decoder.end(Buffer.from([0xAC])));
|
|
```
|
|
|
|
## Class: `StringDecoder`
|
|
|
|
### `new StringDecoder([encoding])`
|
|
|
|
<!-- YAML
|
|
added: v0.1.99
|
|
-->
|
|
|
|
* `encoding` {string} The character [encoding][] the `StringDecoder` will use.
|
|
**Default:** `'utf8'`.
|
|
|
|
Creates a new `StringDecoder` instance.
|
|
|
|
### `stringDecoder.end([buffer])`
|
|
|
|
<!-- YAML
|
|
added: v0.9.3
|
|
-->
|
|
|
|
* `buffer` {Buffer|TypedArray|DataView} A `Buffer`, or `TypedArray`, or
|
|
`DataView` containing the bytes to decode.
|
|
* Returns: {string}
|
|
|
|
Returns any remaining input stored in the internal buffer as a string. Bytes
|
|
representing incomplete UTF-8 and UTF-16 characters will be replaced with
|
|
substitution characters appropriate for the character encoding.
|
|
|
|
If the `buffer` argument is provided, one final call to `stringDecoder.write()`
|
|
is performed before returning the remaining input.
|
|
After `end()` is called, the `stringDecoder` object can be reused for new input.
|
|
|
|
### `stringDecoder.write(buffer)`
|
|
|
|
<!-- YAML
|
|
added: v0.1.99
|
|
changes:
|
|
- version: v8.0.0
|
|
pr-url: https://github.com/nodejs/node/pull/9618
|
|
description: Each invalid character is now replaced by a single replacement
|
|
character instead of one for each individual byte.
|
|
-->
|
|
|
|
* `buffer` {Buffer|TypedArray|DataView} A `Buffer`, or `TypedArray`, or
|
|
`DataView` containing the bytes to decode.
|
|
* Returns: {string}
|
|
|
|
Returns a decoded string, ensuring that any incomplete multibyte characters at
|
|
the end of the `Buffer`, or `TypedArray`, or `DataView` are omitted from the
|
|
returned string and stored in an internal buffer for the next call to
|
|
`stringDecoder.write()` or `stringDecoder.end()`.
|
|
|
|
[encoding]: buffer.md#buffers-and-character-encodings
|