Benchmark: RegEx.test vs. String.includes

Script Preparation code:

var error = "Failed to read the 'localStorage' property from 'Window': Access is denied for this document.";
var regex_1 = /localStorage|sessionStorage/;
var regex_2 = /Access is denied for this document/;

Tests:

RegEx.test
/localStorage|sessionStorage/.test(error) && /Access is denied for this document/.test(error);
String.includes
error && (error.includes('localStorage') || error.includes('sessionStorage')) && error.includes('Access is denied for this document');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
RegEx.test
String.includes

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.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

The provided benchmark is designed to test two different approaches for checking if a string contains certain substrings: using regular expressions (RegEx) with the `test()` method, and using the `includes()` method. We'll break down each approach, their pros and cons, and other considerations.

**Approach 1: RegEx with `test()`**

The first test case uses regular expressions to check if the string `error` contains either "localStorage" or "sessionStorage". The regular expression `/localStorage|sessionStorage/` is used, which matches either of the two substrings. The `test()` method is then called on this regular expression, passing in the `error` string as an argument.

Pros:

* Efficient for checking if a single substring exists in a larger string.
* Can be more readable and maintainable than using multiple calls to `includes()`.
* Can handle complex patterns with anchors, flags, and quantifiers.

Cons:

* May be slower than using `includes()` for simple substring checks due to the overhead of compiling and executing regular expressions.
* Requires knowledge of regular expression syntax and can be less intuitive for non-regex experts.

**Approach 2: `includes()` method**

The second test case uses the `includes()` method to check if the string `error` contains either "localStorage", "sessionStorage", or "Access is denied for this document". This approach involves calling the `includes()` method on the individual substrings, which can be slower than using a single regular expression.

Pros:

* Simple and intuitive to use.
* Fast and efficient for simple substring checks due to the optimized implementation of the `includes()` method in modern browsers.

Cons:

* Requires multiple calls to `includes()`, which can lead to increased overhead and slower performance compared to using a single regular expression.
* May be less readable and maintainable than using RegEx with `test()`.

**Library and special JS features**

In this benchmark, the `localStorage` API is used, which provides a way to store data locally in the browser. The `sessionStorage` API is also used, but it's not explicitly mentioned in the benchmark definition or script preparation code.

**Special JS feature**

There is no special JavaScript feature or syntax used in this benchmark. It solely relies on standard JavaScript features and libraries like RegEx and DOM APIs.

**Alternatives**

If you're looking for alternative approaches to microbenchmarking JavaScript code, some popular options include:

* Benchmark.js: A popular benchmarking library that provides a simple and efficient way to write benchmarks.
* JSPerf: A website that allows users to create and share JavaScript benchmarks, often used for comparing browser performance.
* Test262: A comprehensive test suite for ECMAScript standards and implementations.

In conclusion, the MeasureThat.net benchmark highlights the trade-offs between using regular expressions with `test()` versus the `includes()` method for substring checks. While RegEx can be more efficient and readable, it may require more expertise and knowledge of syntax. The `includes()` method is simple and fast but requires multiple calls and may lead to slower performance.

Related benchmarks:

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

Comparing performance of: RegEx.test vs String.includes

Created: 3 years ago by: Guest

Jump to the latest result

RegEx.test

String.includes

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):