Benchmark: Asterisk map replace vs regex replace

Script Preparation code:

function mapReplace(value) {
  return value.split("").map((x, index, arr) => "*").join("")
}

function regexReplace(value) {
  return value.replace(/./g, "*");
}

Tests:

Map replace
const input = "abcdefghijklmnopqrstuvwxyz"; mapReplace(input);
Regex replace
const input = "abcdefghijklmnopqrstuvwxyz"; regexReplace(input);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Map replace
Regex replace

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark, hosted on MeasureThat.net, is designed to compare two different approaches for replacing characters in a string: `mapReplace` and `regexReplace`. The goal of this benchmark is to measure which approach is faster.

**Options Compared**

Two options are compared:

1. **`mapReplace`**: This function uses the `Array.prototype.map()` method to iterate over each character in the input string, replacing it with an asterisk (`*`). It then joins the modified array back into a string.
2. **`regexReplace`**: This function uses a regular expression to replace all characters in the input string with an asterisk (`*`).

**Pros and Cons of Each Approach**

1. `mapReplace`:
	* Pros: More control over individual character replacements, potentially more efficient for small strings or custom replacement logic.
	* Cons: Iterating over each character individually can be slower than using a regular expression.
2. `regexReplace`:
	* Pros: Faster and more efficient for large strings, as it leverages the optimized performance of regex engines.
	* Cons: Less control over individual character replacements, may require additional processing to handle edge cases.

**Other Considerations**

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

* Size of the input string: For very small strings, `mapReplace` might be faster due to its simplicity. For large strings, `regexReplace` is likely to be faster.
* Custom replacement logic: If you need to replace specific characters or patterns, `mapReplace` provides more control.
* Browser and JavaScript engine support: Ensure both approaches are supported by your target browser and JavaScript engine.

**Library Usage**

The benchmark uses the following library:

* None explicitly mentioned. However, it's likely that the `Array.prototype.map()` method is used internally by modern browsers' JavaScript engines to optimize performance.

**Special JS Features or Syntax**

None mentioned in this benchmark.

**Alternative Approaches**

If you need to replace characters in a string and want to explore alternative approaches, consider:

1. Using a library like `lodash` with its `replace()` function.
2. Implementing a custom replacement function using a loop or recursion.
3. Utilizing a more efficient data structure, such as an array of character codes, for faster replacements.

Keep in mind that these alternatives might not be suitable for all use cases and may incur additional overhead due to their complexity.

Related benchmarks:

Asterisk map replace vs regex replace (version: 0)

Comparing performance of: Map replace vs Regex replace

Created: 6 years ago by: Guest

Jump to the latest result

Map replace

Regex replace

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):