Benchmark: Various regex testing patterns

Script Preparation code:

var string = "Hello world!";
var regex = /[A-Z][a-z]+ [a-z]+/;
var re = new RegExp('[A-Z][a-z]+ [a-z]+');

Tests:

Regex.test
regex.test(string);
String.match
string.match(regex);
Regex.test object
re.test(string)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Regex.test
String.match
Regex.test object

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.4844.74 Safari/537.36

Browser/OS: Chrome 99 on Windows

View result in a separate tab

Test name	Executions per second
Regex.test	4813233.5 Ops/sec
String.match	4424211.5 Ops/sec
Regex.test object	5063032.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested, compared, and some considerations.

**Benchmark Definition**

The benchmark definition is a JSON object that represents a JavaScript microbenchmark. The `Name` field specifies the name of the benchmark, and the `Description` field provides a brief description of the benchmark (although in this case, it's empty).

The `Script Preparation Code` section contains the code that prepares the test environment for each benchmark. In this case, the script creates a string variable `string` with the value "Hello world!" and defines two regular expression objects: `regex` and `re`. The `regex.test(string)` function is not defined anywhere in the provided code, which might be an oversight.

The `Html Preparation Code` section is empty, indicating that no HTML preparation is needed for this benchmark.

**Individual Test Cases**

The test cases are represented as an array of objects. Each object contains a `Benchmark Definition` string that specifies the function to be executed in each test case. The `Test Name` field provides a human-readable name for each test case.

In this benchmark, there are three test cases:

1. `Regex.test(string)`: This test case executes the `regex.test(string)` function.
2. `string.match(regex)`: This test case executes the `string.match(regex)` method.
3. `re.test(string)`: This test case executes the `re.test(string)` function.

**Comparison**

The benchmark is comparing the execution times of these three different approaches:

1. Using an object literal (`regex`) to create a regular expression pattern and then calling its `test()` method on a string.
2. Using the `String.match()` method with the regular expression pattern.
3. Using a `RegExp` object (`re`) created from the regular expression pattern and then calling its `test()` method on the string.

**Pros and Cons**

Here are some pros and cons of each approach:

1. **regex.test(string)**:
	* Pros: This approach creates a new regular expression object for each test case, which might be more efficient in terms of memory usage.
	* Cons: It's unclear why this function is not defined elsewhere in the code, as it's being called from within the benchmark definition.
2. **string.match(regex)**:
	* Pros: This approach uses an existing regular expression pattern and method, making it easier to maintain and understand.
	* Cons: It might be less efficient than creating a new regular expression object for each test case.
3. **re.test(string)**:
	* Pros: Using a `RegExp` object can be more efficient in terms of memory usage, as the same pattern can be reused across multiple test cases.
	* Cons: The `RegExp` constructor is not necessary here, and using an object literal might be simpler.

**Library**

In this benchmark, there are two libraries being used:

1. **RegExp**: The `RegExp` class is used to create regular expression objects (`re`).
2. **String.prototype.match()**: This method is used to execute the regular expression pattern on a string (`string.match(regex)`).

Both of these libraries are built-in to JavaScript and don't require any additional imports.

**Special JS Feature or Syntax**

There doesn't appear to be any special JavaScript feature or syntax being tested in this benchmark. The code is standard JavaScript, using basic operators and data types.

**Other Alternatives**

If the goal of the benchmark is to compare different approaches to executing regular expression patterns on strings, here are some other alternatives that could have been included:

1. Using a regex engine like `esregex` or `regexjs`.
2. Comparing the performance of different JavaScript engines (e.g., V8 vs. SpiderMonkey).
3. Testing the performance of different string processing libraries (e.g., `lodash.string`).

However, these alternatives might not be as relevant to this specific benchmark, which is focused on comparing the execution times of basic regular expression patterns in JavaScript.

Related benchmarks:

Various regex testing patterns (version: 0)

Comparing performance of: Regex.test vs String.match vs Regex.test object

Created: 2 years ago by: Guest

Jump to the latest result

Regex.test

String.match

Regex.test object

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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