Benchmark: Regex vs split/join happily

Script Preparation code:

var str = 'Abcd efghij klmnopqrstuv wxy Abcd efghij klmnopqrstuv wxy Abcd efghij klmnopqrstuv wxyAbcd efghij klmnopqrstuv wxy Abcd efghij klmnopqrstuv wxy Abcd efghij klmnopqrstuv wxy';

Tests:

Regex 2x pro happily on the sea
str.replace(/wxy/g, "Teste");
Split and Join happily 2 ue kd vmaos
str.split('wxy').join('Teste');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Regex 2x pro happily on the sea
Split and Join happily 2 ue kd vmaos

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of MeasureThat.net and explore what's tested in this benchmark.

**Benchmark Overview**

The benchmark is designed to compare two approaches for replacing a substring with another string:

1. Using `str.replace()` with a regular expression (regex) that matches the pattern "wxy" globally (`/wxy/g`).
2. Using `str.split()` and then concatenating the resulting parts back together using `join()`.

**Options Compared**

The benchmark is comparing two different approaches, each with its pros and cons:

* **Regex approach**:
	+ Pros: More efficient for replacing multiple occurrences of a pattern, can be used to perform complex string manipulations.
	+ Cons: Can be slower than other methods due to the overhead of parsing regex patterns. May also lead to security issues if not properly sanitized.
* **Split and Join approach**:
	+ Pros: Simple, straightforward, and easy to understand. Often faster than regex approaches because it doesn't require pattern matching or parsing.
	+ Cons: May be slower for large strings due to the overhead of creating intermediate arrays and concatenating them.

**Library/Feature Considerations**

There is no library explicitly mentioned in this benchmark, but we can assume that `str` is an object with a `replace()` method, which is part of the JavaScript standard library. The `split()` and `join()` methods are also part of the standard library.

If we were to use a library for string manipulation, some popular options include:

* Lodash: Provides a wide range of utility functions, including `str.replace()`, `str.split()`, and `str.join()`.
* String.prototype.replaceAll(): Some browsers support this method as an extension to the `String` prototype.

**Special JS Features/Syntax**

There are no special JavaScript features or syntax mentioned in this benchmark. The code is simple and straightforward, using only standard JavaScript methods and libraries.

**Other Alternatives**

If we were to rewrite this benchmark with alternative approaches, some options might include:

* Using a library like V8's `regexp` or Microsoft's `es6-regex` for regex-based string manipulation.
* Implementing a custom string replacement algorithm using bitwise operations or other low-level techniques.
* Using a different data structure, such as an array of characters or a trie, to store the input string and perform replacements more efficiently.

However, these alternatives might not provide significant performance improvements over the standard library methods used in this benchmark.

Latest run results:

Run details: (Test run date: 6 years ago)

User agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36

Browser/OS: Chrome 69 on Windows 7

View result in a separate tab

Test name	Executions per second
Regex 2x pro happily on the sea	1126820.5 Ops/sec
Split and Join happily 2 ue kd vmaos	970918.9 Ops/sec

Related benchmarks:

Regex vs split/join happily (version: 0)

Comparing performance of: Regex 2x pro happily on the sea vs Split and Join happily 2 ue kd vmaos

Created: 6 years ago by: Guest

Jump to the latest result

Regex 2x pro happily on the sea

Split and Join happily 2 ue kd vmaos

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):