Benchmark: builtin replaceAll vs regex replace

Script Preparation code:

String.prototype.replaceAllRegex = function(search, replacement) {
    var target = this;
    return target.replace(new RegExp(search, 'g'), replacement);
};

Tests:

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

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
replace regex
replace All
replace All Regex

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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Let's break down the provided benchmark and explain what is being tested, the options compared, their pros and cons, and other considerations.

**What is being tested?**

MeasureThat.net is testing the performance difference between three approaches to replace spaces in a string:

1. **builtin replaceAll**: This approach uses the built-in `replaceAll` method of the String prototype.
2. **regex replace**: This approach uses regular expressions (regex) with the `replace` method.
3. **replaceAllRegex**: This approach defines a custom function `replaceAllRegex` that mimics the behavior of `replaceAll`, but uses regex.

**Options compared**

The benchmark compares the performance of these three approaches for replacing spaces in a single string ("this is it"):

* `replaceAll`
* `replace` with regex (`/ /g`)
* `replaceAllRegex` (custom function)

**Pros and cons of each approach**

1. **builtin replaceAll**: This approach is likely to be the fastest, as it's implemented in native JavaScript and optimized for performance. However, it may not work in all situations, such as when using Unicode characters that don't have a space equivalent.
2. **regex replace**: This approach uses regular expressions, which can be slower due to the overhead of pattern compilation and matching. However, regex is often more flexible than string manipulation methods and can handle complex replacements.
3. **replaceAllRegex** (custom function): This approach defines a custom function that mimics the behavior of `replaceAll`. It may have similar performance characteristics to `replaceAll`, but with the added overhead of defining a new function.

**Library and purpose**

None of the benchmarked approaches use any external libraries beyond what's built into JavaScript. However, it's worth noting that some browsers might have additional methods or functions for string manipulation, such as `String.prototype.normalize()`.

**Special JS feature or syntax**

There are no special JS features or syntax used in this benchmark. All three approaches are standard JavaScript methods and functions.

**Other alternatives**

If you're looking for alternative ways to replace spaces in a string, some options include:

* Using the `String.prototype.split` method with an empty array: `"this is it".split(' ').join('+')`
* Using the `String.prototype.replace` method with a callback function: `"this is it".replace(/ /g, function(match) { return '+' })`

Keep in mind that these alternatives may have different performance characteristics compared to the benchmarked approaches.

Overall, this benchmark provides valuable insights into the performance differences between various string replacement methods in JavaScript.

Related benchmarks:

builtin replaceAll vs regex replace (version: 0)

Comparing performance of: replace regex vs replace All vs replace All Regex

Created: 5 years ago by: Guest

Jump to the latest result

replace regex

replace All

replace All Regex

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):