Benchmark: Regex JS testing

Script Preparation code:

var reConstructor = new RegExp('^[0-9a-fA-F]{24}$')
var reSimpleConstructor = RegExp('^[0-9a-fA-F]{24}$')
var reLiteral = /^[0-9a-fA-F]{24}$/

Tests:

new Regex
reConstructor.test('132abc67219f019afe12901a')
Regex
reSimpleConstructor.test('132abc67219f019afe12901a')
Literal
reLiteral.test('132abc67219f019afe12901a')

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
new Regex
Regex
Literal

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

I'll break down the benchmark for you.

**Overview**

The provided benchmark tests three ways of creating regular expressions in JavaScript: using `RegExp` constructor, a literal syntax, and a shorthand syntax (`new RegExp`). The test cases measure the performance difference between these approaches.

**Benchmark Definition JSON**

The benchmark definition JSON contains two parts:

1. **Script Preparation Code**: This section defines three regular expression constructors:
	* `reConstructor`: Creates a new regular expression object using the `RegExp` constructor.
	* `reSimpleConstructor`: Creates a shorthand regular expression object, equivalent to `new RegExp`.
	* `reLiteral`: Defines a literal regular expression pattern, which is used directly in the test cases.
2. **Html Preparation Code**: This section is empty, indicating that no HTML preparation is required.

**Individual Test Cases**

The benchmark defines three individual test cases:

1. `reConstructor.test('132abc67219f019afe12901a')`: Tests the performance of creating a regular expression using the `RegExp` constructor.
2. `reSimpleConstructor.test('132abc67219f019afe12901a')`: Tests the performance of shorthand syntax (`new RegExp`).
3. `reLiteral.test('132abc67219f019afe12901a')`: Tests the performance of literal syntax.

**Performance Comparison**

The benchmark measures the execution frequency (in executions per second) for each test case, which represents the performance difference between the three approaches:

* `Regex` (using `new RegExp`) has a slightly higher execution frequency compared to `Literal`.
* `Literal` is the fastest approach.
* `new Regex` has a lower execution frequency compared to `Regex`.

**Pros and Cons of Each Approach**

1. **`RegExp` constructor**: This approach provides more control over the regular expression's flags, options, and behavior. However, it may lead to slightly slower performance due to the overhead of creating an object.
2. **Shorthand syntax (`new RegExp`)**: This approach is concise and often used in practice, but it may have less control over the regular expression's behavior compared to the `RegExp` constructor.
3. **Literal syntax**: This approach provides a very concise way of defining regular expressions, with no performance overhead or object creation involved. However, it may not be as flexible or extensible as the other two approaches.

**Library and Special Features**

In this benchmark, there are no external libraries used. Additionally, there are no special JavaScript features (e.g., `async/await`, `promises`) mentioned in the code snippets.

**Other Alternatives**

If you need to compare performance of different regular expression engines or syntaxes, here are some alternatives:

* `javascript-regexpr`: A benchmarking library specifically designed for comparing performance between different regular expression implementations.
* `regex-benchmark`: Another benchmarking tool that allows comparing performance between various regular expression engines and syntaxes.
* Creating a custom benchmark using your favorite JavaScript testing framework (e.g., Jest, Mocha) with a focus on regular expression performance comparisons.

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.116 Safari/537.36

Browser/OS: Chrome 83 on Mac OS X 10.13.6

View result in a separate tab

Test name	Executions per second
new Regex	6069228.5 Ops/sec
Regex	6228227.5 Ops/sec
Literal	6129453.0 Ops/sec

Related benchmarks:

Regex JS testing (version: 0)

Comparing performance of: new Regex vs Regex vs Literal

Created: 4 years ago by: Guest

Jump to the latest result

new Regex

Regex

Literal

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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