Benchmark: RegEx.exec vs regex.test qp

Script Preparation code:

var string = "Hello world!";
var regex = /^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2}\.?\d*)(?:Z|([+\-])([\d|:]*))?$/;

Tests:

regex.exec
regex.exec(string);
regex.test
regex.test(string);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
regex.exec
regex.test

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 15_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.2 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 15 on iOS 15.2

View result in a separate tab

Test name	Executions per second
regex.exec	7772280.0 Ops/sec
regex.test	7893363.5 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.

**Benchmark Overview**

The benchmark is designed to compare the performance of two JavaScript methods: `regex.test()` and `regex.exec()`. The test uses regular expressions (regex) to match strings.

**What's being compared?**

Two options are being compared:

1. **`regex.test(string)`**: This method returns a boolean value indicating whether the string matches the regex pattern or not.
2. **`regex.exec(string)`**: This method executes the regex pattern on the input string and returns an array of match groups if any match is found.

**Pros and Cons of each approach**

1. **`regex.test()`**:
	* Pros: Simple, lightweight, and efficient for simple regex patterns.
	* Cons: Only returns a boolean value (true/false), which might not be useful for complex logic.
2. **`regex.exec()`**:
	* Pros: Can return multiple match groups, useful for more complex regex patterns.
	* Cons: More resource-intensive than `test()`, as it executes the entire regex pattern.

**Library and purpose**

No specific library is mentioned in the benchmark definition, but it's likely that the regex engine used is a built-in JavaScript engine (e.g., V8).

**Special JS feature or syntax**

There's no special JavaScript feature or syntax being tested in this benchmark. However, it's worth noting that `regex.exec()` can be affected by certain browser-specific optimizations, such as the use of Just-In-Time (JIT) compilation.

**Other alternatives**

If you need to compare performance between these two methods, you could also consider using other approaches:

1. **`String.prototype.match()`**: This method returns an array of match groups if any match is found, similar to `regex.exec()`.
2. **`String.prototype.search()`**: This method searches for the first occurrence of the regex pattern in the string and returns its position.
3. **Using a different regex engine**: Some libraries (e.g., RegEx.js) provide alternative regex engines that might offer better performance or features.

Keep in mind that each approach has its own trade-offs, and the choice ultimately depends on your specific use case and requirements.

Related benchmarks:

RegEx.exec vs regex.test qp (version: 0)

Comparing performance of: regex.exec vs regex.test

Created: 2 years ago by: Guest

Jump to the latest result

regex.exec

regex.test

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):