Benchmark: Regex vs split/join2

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
str.replace(/m/g, "$&Z");
Split and Join
str.split('').join('Z') + 'Z';

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Regex
Split and Join

Fastest: N/A

Slowest: N/A

Latest run results:

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

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**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The provided benchmark definition json represents two individual test cases: "Regex vs split/join2". This benchmark compares the performance of two approaches to process a specific string.

**Script Preparation Code**

The script preparation code provides a sample string `str` with 28 occurrences of the substring "Abcd efghij klmnopqrstuv wxy". The goal is to replace all these substrings with a modified version using one of the two approaches: regular expressions (`Regex`) or string manipulation using `split()` and `join()` methods (`Split and Join`).

**Benchmark Definition**

The benchmark definition json contains two individual test cases:

1. **Regex**: This test case uses a regular expression to replace all occurrences of "Abcd efghij klmnopqrstuv wxy" with "$&Z", where `$&` is a special regex syntax that refers to the entire matched string, and `Z` is appended to the end of each match.
2. **Split and Join**: This test case uses the `split()` method to split the input string into an array of substrings, joins them with "Z" using the `join()` method, and appends another "Z" at the end.

**Options Compared**

The two approaches are compared in terms of their performance:

* **Regex vs Split and Join**: Both approaches have pros and cons.
	+ **Pros:**
		- Regex is a powerful and flexible pattern matching language.
		- It can handle complex string manipulation tasks with ease.
	+ **Cons:**
		- Performance can be slower compared to other methods like `split()` and `join()`.
		- Regex patterns can become very large and complex, making them harder to read and maintain.
	+ **Pros:**
		- `split()` and `join()` are optimized for performance and easy to understand.
		- They provide a clear and straightforward way to process strings.
	+ **Cons:**
		- May not be suitable for complex string manipulation tasks that require regular expressions.

**Library Used**

In this benchmark, no specific JavaScript library is used. The `split()` and `join()` methods are built-in ECMAScript methods, and the regex pattern in the "Regex" test case uses only basic regex syntax without any external libraries.

**Special JS Feature or Syntax**

The benchmark uses special regex syntax `$&` to refer to the entire matched string. This is a standard regex feature that allows capturing groups in patterns.

**Other Alternatives**

If you want to try alternative approaches, here are some options:

* **Using `replace()` method**: You can use the `replace()` method with a callback function to achieve similar results as the "Regex" approach.
* **Using `String.prototype.replace()` with an arrow function**: Similar to the above suggestion, but using an arrow function for better performance and readability.
* **Using `String.prototype.split()`, `Array.prototype.map()`, and `String.prototype.join()`**: You can use these methods in combination to achieve similar results as the "Split and Join" approach.

In summary, this benchmark allows you to compare the performance of two approaches: regular expressions (`Regex`) versus string manipulation using `split()` and `join()` methods. Both approaches have pros and cons, and understanding these differences will help you make informed decisions about which approach to use in your own JavaScript projects.

Related benchmarks:

Regex vs split/join2 (version: 0)

Comparing performance of: Regex vs Split and Join

Created: 6 years ago by: Guest

Jump to the latest result

Regex

Split and Join

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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