Benchmark: Regex Replace vs native replaceAll

Tests:

replace regex
"string--with--dashes".replace(/--/g, "-");
replace All
"string--with--dashes".replaceAll("--", "-");

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
replace regex
replace All

Fastest: N/A

Slowest: N/A

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

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**Benchmark Overview**

The provided JSON represents a JavaScript microbenchmark test case on MeasureThat.net, which compares the performance of two replacement approaches: regular expression-based (`regex`) and string method-based (`replaceAll`). The test is designed to measure the execution speed of these two methods in replacing dashes with hyphens in a specific input string.

**Options Compared**

The benchmark tests two options:

1. **Regular Expression-Based (`regex`)**: This approach uses the `replace()` method with a regular expression pattern `/--/g`. The regular expression matches one or more consecutive dashes (`--`) and replaces them with a single hyphen (`-`). The `g` flag at the end of the pattern makes the replacement global, so all occurrences are replaced.
2. **String Method-Based (`replaceAll`)**: This approach uses the `replaceAll()` method with two string arguments: `"-"` (hyphen) as the old substring and `"-"` (hyphen again) as the new substring.

**Pros and Cons**

**Regular Expression-Based (`regex`)**

Pros:

* Can handle more complex replacement patterns, including multiple consecutive matches.
* Can be used for other types of text processing, such as searching and validating strings.

Cons:

* May have performance overhead due to the complexity of regular expressions.
* Requires explicit specification of the pattern to match (e.g., `/--/g`).

**String Method-Based (`replaceAll`)**

Pros:

* Typically faster than regular expression-based approaches since it's a simple string replacement.
* Does not require explicit specification of patterns.

Cons:

* May not handle more complex replacement patterns as well as `regex`.
* Limited to replacing single characters or substrings (in this case, just two dashes).

**Library and Purpose**

In both test cases, the input string is created using JavaScript template literals (`"string--with--dashes"`). The library used here is part of the JavaScript standard library.

**Special JS Feature or Syntax**

There are no special features or syntaxes explicitly mentioned in this benchmark. However, it's worth noting that modern JavaScript engines (including those used by Firefox 101) support several advanced features, such as `const` and arrow functions, which may affect performance in certain contexts.

**Other Alternatives**

If you're interested in exploring alternative approaches for string replacement or regular expression use cases, here are a few examples:

* For simple string replacements, consider using `replace()` with a regex pattern (e.g., `/-/g`).
* For more complex text processing tasks, consider using a dedicated library like `regex-js` or `lodash`.
* If you need to perform multiple operations on strings, consider using a functional programming approach (e.g., chaining methods).

Keep in mind that the choice of approach ultimately depends on your specific use case and performance requirements.

Related benchmarks:

Regex Replace vs native replaceAll (version: 0)

Comparing performance of: replace regex vs replace All

Created: 3 years ago by: Guest

Jump to the latest result

replace regex

replace All

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):