Benchmark: Regex vs String.includes in Array.filter v2

Script Preparation code:

var array = ["PHV Versicherung", "Rücktrittsversicherung", "Lebensversicherung"]
var searchStrings = ["rücktritt", "versicher", "rung", "P"]

Tests:

Regex match
for(let i = 0; i < searchStrings; i++) { array.filter(str => { const rgx = new RegExp(searchStrings[i], "i"); return str.match(rgx); }) }
String includes with toLowerCase
for(let i = 0; i < searchStrings; i++) { array.filter(str => { return str.toLowerCase().includes(searchStrings[i].toLowerCase()); }) }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Regex match
String includes with toLowerCase

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36

Browser/OS: Chrome 128 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Regex match	5353582.5 Ops/sec
String includes with toLowerCase	5393952.5 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

The benchmark is designed to compare two approaches:

1. **Regular Expressions (Regex)**: This approach uses the `RegExp` constructor to create a regular expression pattern, which is then used to search for matches in an array of strings.
2. **String `includes()` method**: This approach uses the `includes()` method to check if a string contains a specific substring.

**Options Compared**

The benchmark compares the performance of these two approaches on an array of strings that contain various substrings, including "rücktritt", "versicher", "rung", and "P".

**Pros and Cons of Each Approach**

1. **Regular Expressions (Regex)**:
	* Pros:
		+ Can be more flexible than the `includes()` method, as it can match patterns with variables and quantifiers.
		+ Can be used to extract data from strings that don't contain the expected substring.
	* Cons:
		+ Can be slower than the `includes()` method for simple string searches.
		+ Requires more memory and CPU resources to compile the regular expression pattern.
2. **String `includes()` method**:
	* Pros:
		+ Faster than the Regex approach, especially for small strings or simple searches.
		+ Simpler to implement and less prone to errors.
	* Cons:
		+ Less flexible than Regex, as it only checks for exact substring matches.
		+ May not be suitable for advanced string matching tasks.

**Library Used**

In this benchmark, no specific library is required. The `RegExp` constructor and the `includes()` method are built-in JavaScript functions.

**Special JS Features or Syntax**

The benchmark uses the following special features:

* **Template literals**: Used in the script preparation code to create a template string for the array initialization.
* **Arrow functions**: Used in the benchmark definitions to define small, anonymous functions.

**Other Alternatives**

If you wanted to use different approaches, here are some alternatives:

1. **String `indexOf()` method**: Instead of using `includes()`, you could use `indexOf()` to find the index of the first occurrence of a substring.
2. **S regex**: You could also use a simple regular expression like `/rücktritt/i` instead of creating a full-fledged RegExp object.
3. **Native JavaScript functions**: Depending on the specific requirements, other native JavaScript functions like `String.prototype.replace()` or `String.prototype.matchAll()` might be more suitable.

Keep in mind that the performance differences between these alternatives will depend on the specific use case and hardware configuration.

Related benchmarks:

Regex vs String.includes in Array.filter v2 (version: 0)

Comparing performance of: Regex match vs String includes with toLowerCase

Created: one year ago by: Guest

Jump to the latest result

Regex match

String includes with toLowerCase

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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