Benchmark: TextDecoder plus array initialization vs String.fromCharCode

Script Preparation code:

var bytes = [84,104,105,115,32,105,115,32,97,32,115,97,109,112,108,101,32,112,97,114,97,103,114,97,112,104,46];
var bufferArray = new Uint16Array(bytes);
var decoder = new TextDecoder(); // default 'utf-8' or 'utf8'

Tests:

String.fromCharCode
String.fromCharCode.apply(null, bufferArray);
TextDecoder
decoder.decode(bufferArray);
TextDecoder plus array
decoder.decode(new Uint8Array(bytes));
TextDecoder plus constructor and array
new TextDecoder().decode(new Uint8Array(bytes));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
String.fromCharCode
TextDecoder
TextDecoder plus array
TextDecoder plus constructor and array

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (Android 15; Mobile; rv:148.0) Gecko/148.0 Firefox/148.0

Browser/OS: Firefox Mobile 148 on Android

View result in a separate tab

Test name	Executions per second
String.fromCharCode	2471663.0 Ops/sec
TextDecoder	3649601.2 Ops/sec
TextDecoder plus array	2281511.0 Ops/sec
TextDecoder plus constructor and array	965158.8 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark JSON and explain what's being tested.

**Benchmark Definition**
The provided benchmark is testing the performance of three different approaches to decode a Uint16Array:

1. `String.fromCharCode.apply(null, bufferArray)`
2. `decoder.decode(bufferArray)`
3. `decoder.decode(new Uint8Array(bytes))`
4. `new TextDecoder().decode(new Uint8Array(bytes))`

**Options Compared**

The benchmark is comparing the performance of the following options:

* Using `String.fromCharCode` to create a string from an array of code points
* Using `TextDecoder` to decode a Uint16Array or Uint8Array

**Pros and Cons of Each Approach**

1. **String.fromCharCode.apply(null, bufferArray)**
	* Pros:
		+ Lightweight, no dependencies required
	* Cons:
		+ Performance can be slow due to the need for explicit looping
		+ Limited control over encoding and decoding settings
2. **decoder.decode(bufferArray)**
	* Pros:
		+ More efficient than `String.fromCharCode` due to optimized decoder logic
		+ Provides more control over encoding and decoding settings (e.g., `encoding`, `fatal` options)
	* Cons:
		+ Requires a separate instance of `TextDecoder` for each call
3. **decoder.decode(new Uint8Array(bytes))**
	* Pros:
		+ Similar to the first option, but with a more convenient way to create an array for decoding
	* Cons:
		+ May incur additional overhead due to the creation of a new Uint8Array instance
4. **new TextDecoder().decode(new Uint8Array(bytes))**
	* Pros:
		+ Provides more control over encoding and decoding settings (e.g., `encoding`, `fatal` options)
		+ More flexible than using `decoder.decode()` directly
	* Cons:
		+ May incur additional overhead due to the creation of a new instance of `TextDecoder`

**Library: TextDecoder**
The `TextDecoder` library is part of the Web APIs specification and provides an efficient way to decode binary data into text. It's designed to work with various encodings, including UTF-8, UTF-16, and others.

**Special JS Feature/Syntax**
None mentioned in this specific benchmark.

**Other Alternatives**

In addition to the options tested by this benchmark, other alternatives for decoding UintArrays or Uint8Arrays include:

* Using `atob()` (ASCII) or `btoa()` (Base64) for simple encoding/decoding tasks
* Utilizing third-party libraries like `iconv-lite` or `chardet` for more advanced encoding and decoding scenarios

Keep in mind that these alternatives may have different performance characteristics, dependencies, and use cases compared to the options tested by this benchmark.

Related benchmarks:

TextDecoder plus array initialization vs String.fromCharCode (version: 0)

Comparing performance of: String.fromCharCode vs TextDecoder vs TextDecoder plus array vs TextDecoder plus constructor and array

Created: 2 years ago by: Guest

Jump to the latest result

String.fromCharCode

TextDecoder

TextDecoder plus array

TextDecoder plus constructor and array

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):