Benchmark: Global matching regex with and without + char

Script Preparation code:

var dummyString = 'Hello';
var iterations  = 1000;

Tests:

With +
for (var i = 0; i < iterations; i++) { dummyString.replace(/[^a-z0-9]+/gi, ''); }
Without +
for (var i = 0; i < iterations; i++) { dummyString.replace(/[^a-z0-9]/gi, ''); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
With +
Without +

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested, compared options, pros and cons of those approaches, and other considerations.

**Benchmark Overview**

The benchmark measures the performance of two different regular expression (regex) patterns: `/[^a-z0-9]+/gi` and `/[^a-z0-9]/gi`. Both patterns are used in a replace function to remove non-alphanumeric characters from a string. The main difference between the two patterns is the presence or absence of the `+` character, which affects how many matches are considered.

**Pattern Options**

1. **/[^a-z0-9]+/gi**: This pattern uses the `+` character, which matches one or more occurrences of the preceding element (in this case, non-alphanumeric characters). The `i` flag makes the match case-insensitive.
	* Pros: Easy to read and understand, allows for efficient matching of multiple occurrences.
	* Cons: Can be slower due to the need to count the number of matches, which may lead to unnecessary processing.
2. **/[^a-z0-9]/gi**: This pattern uses a single character `/` instead of `+`, which matches a single non-alphanumeric character. The `i` flag remains the same as in the first pattern.
	* Pros: Generally faster than the `+` version, as it only needs to make a single pass through the string.
	* Cons: May be less readable and more prone to errors due to the lack of clarity in its purpose.

**Library Used**

There is no specific library mentioned in the benchmark definition. The regex patterns are part of the standard JavaScript syntax.

**Special JS Feature/Syntax**

None explicitly mentioned. However, the use of the `replace()` function with a callback (empty string) and the `for` loop to iterate over the iterations is common JavaScript syntax.

**Other Considerations**

The benchmark only measures the performance difference between these two patterns in a replace function. This might not be representative of real-world usage scenarios, where different factors like the input data, context, or surrounding code might influence performance.

For more comprehensive testing, you could consider adding additional test cases, such as:

* Using other regex patterns (e.g., `/[^a-z0-9]*/i` or `/[\W]+/gi`)
* Testing with different input data (e.g., strings with varying lengths or character sets)
* Examining performance under different execution environments (e.g., Node.js, browser, or mobile)

**Alternatives**

For more advanced regex testing or benchmarking, consider using libraries like:

* `regex-performance-test`: A lightweight library for measuring the performance of regex patterns.
* `benchmark`: A popular JavaScript benchmarking library that supports various test cases and execution environments.

Keep in mind that these alternatives might offer more features and flexibility than what's provided by MeasureThat.net, but they may also introduce additional complexity.

Latest run results:

Run details: (Test run date: 7 years ago)

User agent: Mozilla/5.0 (X11; Linux i686) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.98 Safari/537.36

Browser/OS: Chrome 57 on Linux

View result in a separate tab

Test name	Executions per second
With +	667.3 Ops/sec
Without +	660.1 Ops/sec

Related benchmarks:

Global matching regex with and without + char (version: 0)

Comparison of performance of /[^a-z0-9]+/gi vs /[^a-z0-9]/gi in replace function, i.e. one vs many matches

Comparing performance of: With + vs Without +

Created: 7 years ago by: Guest

Jump to the latest result

With +

Without +

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):