Benchmark: RegEx.test vs String.startsWith

Script Preparation code:

var appState = "/pt";
var regex = /(\/\w{2}\/)|(\/\w{2}$)/;
var arr = ['en', 'es', 'fr', 'de', 'pt', 'nl'];

Tests:

RegEx.test
regex.test(appState);
Array.startsWith
arr.find((l) => appState.startsWith(`/${l}/`))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
RegEx.test
Array.startsWith

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

I'd be happy to explain the benchmark and its results.

**Benchmark Overview**

The benchmark is designed to compare the performance of two different approaches: using the `regex.test()` method and using the `Array.prototype.startsWith()` method to test if a string matches a certain pattern. The test cases are run on JavaScript strings with specific patterns and values, including a specific state (`appState`) that contains the `/pt` path.

**Options Compared**

The two options being compared are:

1. **regex.test()**: This method tests if the entire regular expression pattern matches the string. It's a more explicit approach that may be slower due to its complexity.
2. **Array.prototype.startsWith()**: This method checks if the string starts with a specified value. In this case, it's used to check if the `appState` string starts with `/pt`. This approach is often faster than `regex.test()` because it's a simpler operation.

**Pros and Cons**

* **regex.test():**
	+ Pros: More explicit and clear, can be useful in complex scenarios.
	+ Cons: May be slower due to its complexity.
* **Array.prototype.startsWith():**
	+ Pros: Faster, more concise, and widely supported.
	+ Cons: May not work as expected if the pattern is complex or edge cases are involved.

**Library Usage**

The benchmark uses the `String.prototype.startsWith()` method, which is a part of the JavaScript language standard. It's used to check if the `appState` string starts with the specified value (`/pt`).

**Special JS Features or Syntax**

There aren't any special features or syntax mentioned in the benchmark. The code is straightforward and uses only built-in JavaScript methods.

**Other Considerations**

When running this benchmark, it's essential to consider the following:

* The performance of regular expression tests can vary depending on the complexity of the pattern.
* The use of `Array.prototype.startsWith()` may not be suitable for all scenarios, especially if the array values contain complex patterns or edge cases.
* Benchmarking results can also depend on factors like JavaScript engine optimizations, caching, and hardware.

**Alternatives**

If you want to run this benchmark with different options or test other approaches, here are some alternatives:

1. Use a different regular expression library (e.g., `RegExp`) instead of the built-in `regex.test()` method.
2. Implement your own custom string matching function to compare with `Array.prototype.startsWith()`.
3. Test with different JavaScript engines or versions to observe potential performance variations.
4. Run additional benchmark tests on other aspects, such as parsing speed, execution time, or memory usage.

Keep in mind that these alternatives may require modifications to the benchmark code and setup to ensure accurate results.

Related benchmarks:

RegEx.test vs String.startsWith (version: 0)

Comparing performance of: RegEx.test vs Array.startsWith

Created: 2 years ago by: Guest

Jump to the latest result

RegEx.test

Array.startsWith

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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