Benchmark: _last vs regex - MeasureThat.net

HTML Preparation code:

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.21/lodash.min.js"></script>

Tests:

_last
const url = 'https://bo.test.danim.com/template/list/item/aeda0cf9-4f25-4d93-ba14-f8d5635a2817'; const id = _.last(url.split('/')); console.log(id);
regex
const url = 'https://bo.test.danim.com/template/list/item/aeda0cf9-4f25-4d93-ba14-f8d5635a2817'; const regex = /\/item\/([a-z0-9-]+)/; const match = regex.exec(url); const id = match[1]; console.log(id);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
_last
regex

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

I'll provide an explanation of the benchmark, options compared, pros and cons of each approach, library usage, special JavaScript features or syntax, and alternatives.

**Benchmark Overview**

The provided JSON represents two test cases for measuring performance differences between using the `_.last()` method from Lodash and regular expressions (regex) in JavaScript. The test cases are:

1. `_last`: Uses the `_.last()` method to extract the last part of a URL.
2. `regex`: Uses regex to extract the last part of a URL.

**Options Compared**

The two options being compared are:

A. Using the `_.last()` method from Lodash
B. Using regular expressions (regex)

**Pros and Cons of Each Approach**

**A. Using the `_last()` method from Lodash**

Pros:

* Easier to read and write, as it's a concise way to extract the last part of a string.
* Less error-prone, as it's a standardized function with well-defined behavior.

Cons:

* May be slower than regex for large strings due to the overhead of calling a JavaScript function.
* Requires including Lodash in the project, which may add unnecessary dependencies.

**B. Using regular expressions**

Pros:

* Highly optimized and efficient, making it suitable for large-scale performance-critical applications.
* Can be more flexible than `_last()` with support for complex pattern matching.

Cons:

* More error-prone due to the complexity of regex patterns.
* Less readable and maintainable, especially for developers without prior experience with regex.

**Library Usage**

Lodash is a popular JavaScript library that provides various utility functions, including `_.last()`. The inclusion of Lodash in the project adds dependencies and potential overhead. However, it can simplify code and make it more efficient for certain tasks.

**Special JavaScript Features or Syntax**

There are no special JavaScript features or syntax used in these test cases, except for the use of Lodash's `_.last()` method. If you're not familiar with Lodash, it's a simple way to access the last element of an array (or string, in this case).

**Alternatives**

If you don't want to include Lodash or prefer regex over `_last()`, you can consider the following alternatives:

* Use the `split()` method and index manipulation to extract the last part of the URL: `const url = 'https://bo.test.danim.com/template/list/item/aeda0cf9-4f25-4d93-ba14-f8d5635a2817'; const parts = url.split('/'); const id = parts[parts.length - 1];`
* Use a regex that extracts the last part of the URL without relying on Lodash: `const url = 'https://bo.test.danim.com/template/list/item/aeda0cf9-4f25-4d93-ba14-f8d5635a2817'; const regex = /\/([a-z0-9-]+)/; const match = regex.exec(url); const id = match[1];`

Keep in mind that these alternatives may be less efficient or more error-prone than using `_last()` with Lodash.

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.0.0 Safari/537.36

Browser/OS: Chrome 109 on Linux

View result in a separate tab

Test name	Executions per second
_last	188209.4 Ops/sec
regex	242991.4 Ops/sec

Related benchmarks:

_last vs regex (version: 0)

Comparing performance of: _last vs regex

Created: one year ago by: Guest

Jump to the latest result

_last

regex

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):