Benchmark: match vs test vs prepared regex

Script Preparation code:

var str = "@EndUserText.label"
var rePrep = /^[0-9a-fA-F\-]+$/

Tests:

match
var re = /^[0-9a-zA-Z-_@.#\-]+$/ var match = str.match(re);
test
var re = /^[0-9a-zA-Z-_@.#\-]+$/ var match = re.test(str);
test prepared Regex
var match = rePrep.test(str);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
match
test
test prepared Regex

Fastest: N/A

Slowest: N/A

Latest run results:

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

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I'll break down the benchmark and explain what's being tested, compared options, pros and cons, and other considerations.

**Benchmark Overview**

The benchmark measures the performance of three different approaches to test regular expressions (regex) on a given string:

1. `match()`: The built-in JavaScript method for matching a pattern in a string.
2. `test()`: Another built-in JavaScript method for testing if a pattern matches at the beginning of a string.
3. `prepared regex` (using a precompiled regex): Creating a new regex object using a literal string, which is then used to test the input string.

**Comparison Options**

The three options being compared are:

* `match()`: The built-in method for matching patterns in strings. It scans the entire string from left to right and returns an array of matches.
* `test()`: Another built-in method for testing if a pattern matches at the beginning of a string. It only checks if the pattern matches, without scanning the entire string.

**Pros and Cons**

Here's a brief summary of each approach:

* `match()`:
	+ Pros: Can be used to extract matches from the entire string.
	+ Cons: Scans the entire string, which can be slower for large inputs.
* `test()`: 
	+ Pros: Faster than `match()` since it only checks if the pattern matches at the beginning of the string.
	+ Cons: Returns a boolean value indicating whether the match is found or not, but doesn't provide any information about the actual match.
* `prepared regex`:
	+ Pros: Can be faster than `test()` since the regex object can be cached and reused.
	+ Cons: Requires manual handling of the precompiled regex object, which can add overhead.

**Other Considerations**

* The benchmark assumes that the input string contains only valid characters for the specified regex pattern (alphanumeric characters with a hyphen and some special characters). This might not be representative of real-world scenarios where the input may contain invalid or unexpected characters.
* The `executionsPerSecond` value is likely measured in a way that's specific to the test environment, so it might not be directly comparable across different platforms.

**Library and Special JS Features**

None of the individual test cases use any external libraries beyond the standard JavaScript `String` and `RegExp` objects. There are no special JS features or syntax used in these benchmark definitions.

**Alternatives**

There are alternative approaches to testing regex patterns, such as:

* Using a dedicated regex library like [regex-js](https://github.com/leannemcregan/regex-js) or [fast-regex](https://github.com/bblimke/fast-regex), which may provide performance optimizations and improved error handling.
* Utilizing modern JavaScript features like `String.prototype.replace()` with a callback function to test regex patterns.

However, these alternatives are not relevant to this specific benchmark, which focuses on the built-in methods of JavaScript's `String` and `RegExp` objects.

Related benchmarks:

match vs test vs prepared regex (version: 0)

Comparing performance of: match vs test vs test prepared Regex

Created: 6 years ago by: Registered User

Jump to the latest result

match

test

test prepared Regex

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):