Benchmark: Global regex replace vs replaceAll

Tests:

replaceAll
"this is it".replaceAll(" ", "+");
Regex
"this is it".replace(/ /g, "+");

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
replaceAll
Regex

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36 Edg/145.0.0.0

Browser/OS: Chrome 145 on Windows

View result in a separate tab

Test name	Executions per second
replaceAll	5119097.5 Ops/sec
Regex	6148540.5 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the provided JSON and explain what's being tested, the different approaches compared, their pros and cons, and other considerations.

**Benchmark Definition**

The benchmark definition is empty, which means that it doesn't specify any particular test case or scenario. In this case, we need to infer the test cases from the individual test cases listed later.

**Individual Test Cases**

We have two test cases:

1. `replaceAll`
	* Script Preparation Code: None (empty string)
	* Html Preparation Code: None (empty string)

This test case performs a global replacement of spaces (`"  "`) with pluses (`"+"`).

2. `Regex`
	* Script Preparation Code: None (empty string)
	* Html Preparation Code: None (empty string)

This test case uses regular expressions to replace spaces (`"  "` with `"+`).

**Library**

There is no library explicitly mentioned in the provided JSON. However, we can assume that both test cases are using built-in JavaScript functions for string manipulation.

**JavaScript Features/Syntax**

There is a special JavaScript feature used in these test cases: regular expressions (`/regex/`). Regular expressions are a way to search and manipulate text patterns in strings. In this case, the `replaceAll` function uses the `g` flag at the end of the pattern `/ /g`, which means "global" replacement, replacing all occurrences in the string, not just the first one.

**Approaches Compared**

The two test cases compare different approaches to achieve similar results:

1. **`replaceAll`**: This method is a part of the JavaScript `String.prototype.replaceAll()` function and is generally faster than regular expressions for simple replacement tasks.
2. **`Regex`**: This approach uses regular expressions to replace spaces with pluses. While it works, it's slower than using `replaceAll` due to the overhead of parsing and executing the regex pattern.

**Pros and Cons**

* `replaceAll`:
	+ Pros: Faster, more efficient for simple replacement tasks.
	+ Cons: Limited flexibility, may not work with complex text patterns.
* `Regex`:
	+ Pros: Flexible, can handle complex text patterns, but slower than `replaceAll`.
	+ Cons: Slower, may have performance issues if the regex pattern is complex.

**Other Considerations**

When choosing between these two approaches, consider the following factors:

* **Performance**: If speed is critical and you're only dealing with simple replacement tasks, `replaceAll` might be a better choice.
* **Flexibility**: If you need to handle more complex text patterns or want to use other features like capturing groups or anchoring, regular expressions (`Regex`) might be a better option.

**Alternatives**

If you need alternative approaches, consider the following:

1. **`replace()` without global flag**: This method is similar to `replaceAll`, but it only replaces the first occurrence instead of all occurrences.
2. **Using a regex library**: There are many JavaScript regex libraries available that can simplify regular expression usage and provide additional features.
3. **String manipulation functions**: Other string manipulation functions like `split()`, `join()`, or `replace()` might be more suitable depending on your specific use case.

Keep in mind that the best approach depends on the specific requirements of your project, and these alternatives might not always offer significant performance improvements over `replaceAll` and regular expressions.

Related benchmarks:

Global regex replace vs replaceAll (version: 0)

Comparing performance of: replaceAll vs Regex

Created: 3 years ago by: Guest

Jump to the latest result

replaceAll

Regex

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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