Benchmark: Test regexp vs startsWith

Script Preparation code:

var regexp = /^[iv]-/;

function test(value) {
	return value.startsWith('i-') || value.startsWith('v-');
}

Tests:

Using regexp
regexp.test('i-dynamic-page');
Using startsWith
test('i-dynamic-page');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Using regexp
Using startsWith

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark is designed to compare the performance of two different approaches: using a regular expression (`regexp`) and using the `startsWith` method.

The script preparation code defines a regular expression (`var regexp = /^[iv]-/;`) that matches strings starting with 'i-' or 'v-'. The test function (`function test(value) { ... }`) uses this regular expression to check if a given string starts with 'i-' or 'v-'.

**Options Compared**

Two options are compared:

1. **Regular Expression (RegExp)**: The first option uses the `RegExp` object to match strings starting with 'i-' or 'v-'. This approach is typically used for pattern matching and can be slower due to the complexity of the regular expression.
2. **startsWith Method**: The second option uses the `startsWith` method, which is a built-in string method in JavaScript that checks if a string starts with a specified prefix.

**Pros and Cons**

* **RegExp:**
	+ Pros:
		- Can match complex patterns (e.g., 'aabbcc').
		- Can be used for more advanced text processing tasks.
	+ Cons:
		- Typically slower due to the overhead of regular expression execution.
		- Requires explicit pattern definition, which can make it harder to read and maintain.
* **startsWith Method:**
	+ Pros:
		- Faster and more lightweight than RegExp.
		- Easier to read and maintain due to its simplicity.
	+ Cons:
		- Limited to simple prefix matching (e.g., 'i-').

**Other Considerations**

The benchmark may also consider other factors, such as:

* **Browser vs. Engine**: The test results show different execution times for the same string between Yandex Browser 24 and Chrome/124.0.0.0.
* **Device Platform and Operating System**: The test results are specific to a desktop Mac OS X 10.15.7.

**Library and Special JS Features**

There are no libraries mentioned in this benchmark, as it only uses built-in JavaScript methods (`RegExp` and `startsWith`). No special JS features are used, as the code is straightforward and does not employ any advanced or experimental features.

**Alternatives**

Other alternatives for string matching could include:

* **String.prototype.includes()**: Another built-in method that checks if a string contains a specified substring.
* **Text Search Algorithms**: More advanced algorithms like Aho-Corasick or Boyer-Moore, which can be more efficient for specific use cases but may have additional complexity and overhead.

Latest run results:

Run details: (Test run date: 3 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 YaBrowser/24.6.0.0 Safari/537.36

Browser/OS: Yandex Browser 24 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Using regexp	17259794.0 Ops/sec
Using startsWith	22594900.0 Ops/sec

Related benchmarks:

Test regexp vs startsWith (version: 0)

Comparing performance of: Using regexp vs Using startsWith

Created: 3 months ago by: Registered User

Jump to the latest result

Using regexp

Using startsWith

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):