Benchmark: RegExp constructor vs literal vs inline literal

Script Preparation code:

var reConstructor = new RegExp('^[0-9a-fA-F]{24}$')
var reLiteral = /^[0-9a-fA-F]{24}$/

Tests:

new RegExp()
reConstructor.test('132abc67219f019afe12901a')
Literal
reLiteral.test('132abc67219f019afe12901a')
Inline literal
/^[0-9a-fA-F]{24}$/.test('132abc67219f019afe12901a')

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
new RegExp()
Literal
Inline literal

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 dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**Benchmark Definition**

The benchmark is designed to compare the performance of three different approaches:

1. **RegExp constructor**: Creating a new `RegExp` object using the `new RegExp()` syntax.
2. **Literal regex**: Using a regular expression literal, enclosed in forward slashes (`/.../`).
3. **Inline literal**: Using an inline regular expression, with no delimiters (e.g., `/^[0-9a-fA-F]{24}$/.test('string')`).

**Options Compared**

The three options are compared in terms of their performance, measured by the number of executions per second.

**Pros and Cons of Each Approach**

1. **RegExp constructor**:
	* Pros: Can be more readable and maintainable for complex regular expressions.
	* Cons: May incur a performance overhead due to object creation and parsing.
2. **Literal regex**:
	* Pros: Can be faster since the browser can optimize literals as simple patterns.
	* Cons: May not be as readable or maintainable, especially for complex patterns.
3. **Inline literal**:
	* Pros: Can be even faster than literal regex, as it avoids the overhead of creating a new RegExp object.
	* Cons: May be less readable and more prone to errors due to the lack of explicit delimiters.

**Library Used**

None explicitly mentioned in this benchmark definition. However, in other benchmarks on MeasureThat.net, libraries like `lodash` or `moment.js` are often used for specific tasks.

**Special JS Feature or Syntax (Not Applicable)**

No special JavaScript features or syntax are used in this benchmark.

**Other Alternatives**

If you need to test similar regular expression performance, consider using other approaches:

1. **Using a regex engine**: Some browsers have built-in regex engines that can be used for optimized testing.
2. **Using a virtual DOM**: Some libraries, like React, use virtual DOMs to optimize rendering and can also be used for benchmarking.
3. **Using a custom parser**: For extremely performance-critical scenarios, writing a custom parser or using an existing one (e.g., `jsregex`) might be necessary.

Keep in mind that these alternatives may require additional setup, expertise, and resources compared to the original benchmark definition on MeasureThat.net.

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/111.0

Browser/OS: Firefox 111 on Windows

View result in a separate tab

Test name	Executions per second
new RegExp()	14231774.0 Ops/sec
Literal	14631211.0 Ops/sec
Inline literal	13742385.0 Ops/sec

Related benchmarks:

RegExp constructor vs literal vs inline literal (version: 0)

Testing performance when using a new RegExp object vs a literal regex

Comparing performance of: new RegExp() vs Literal vs Inline literal

Created: one year ago by: Guest

Jump to the latest result

new RegExp()

Literal

Inline literal

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):