Benchmark: Inline array vs regex

Script Preparation code:

var ButtonIconPosition = {
    Left: 'left',
    Right: 'right',
}

Tests:

Regex instance and check
for (let i=0; i<1_000_000; i += 1) { const checker = new RegExp( `(${ButtonIconPosition.Left}|${ButtonIconPosition.Top})`, ) }
Array instance and check
for (let i=0; i<1_000_000; i += 1) { const checker = [ButtonIconPosition.Left, ButtonIconPosition.Right] }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Regex instance and check
Array instance and check

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:123.0) Gecko/20100101 Firefox/123.0

Browser/OS: Firefox 123 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
Regex instance and check	8.5 Ops/sec
Array instance and check	1813.4 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Explanation**

The provided benchmark compares two approaches for checking values in an array: using a regular expression (regex) and using the array itself.

**Options Compared**

Two options are compared:

1. **Regex instance**: This approach uses a regex pattern to check if a value is present in the `ButtonIconPosition` object. The regex pattern matches either the "Left" or "Right" values.
2. **Array instance**: This approach simply checks if the value is present in the array `[ButtonIconPosition.Left, ButtonIconPosition.Right]`.

**Pros and Cons**

* **Regex instance**:
	+ Pros: Can be more flexible and powerful for complex pattern matching.
	+ Cons: May have slower performance due to the overhead of creating a regex object and executing the pattern.
	+ Considerations: Regex can be brittle and prone to errors if not used carefully. Additionally, regex engines may not be optimized for JavaScript and can lead to performance issues.
* **Array instance**:
	+ Pros: Simple, fast, and easy to understand.
	+ Cons: Limited flexibility compared to regex.
	+ Considerations: This approach assumes that the values in the array are always present in the `ButtonIconPosition` object. If the order or value of the array changes, this approach may break.

**Library**

The `RegExp` class is used in the benchmark. It provides a way to define and execute regular expression patterns in JavaScript.

**Special JS Feature/Syntax**

None mentioned in this specific benchmark.

**Other Alternatives**

If you need more flexibility or performance, you could consider using:

* **String.includes()**: A method that checks if a string includes a specified value.
* **Array.indexOf()**: A method that returns the index of a value in an array, or -1 if not found.
* **Regex alternatives**: Other regex engines like V8's `RegExp` engine or specialized libraries like `regex-js`.

Note: The benchmark is designed to compare performance between these two approaches. If you need more control over the test or want to explore other optimizations, consider modifying the benchmark code or using a different testing framework.

Related benchmarks:

Inline array vs regex (version: 0)

Comparing performance of: Regex instance and check vs Array instance and check

Created: 2 years ago by: Registered User

Jump to the latest result

Regex instance and check

Array instance and check

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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