Benchmark: replacer string vs function 2

Script Preparation code:

var testCase = 'local';
var testRegex = /(o)c(a)/g;
var testReplaceText = '$1$2';
var testReplaceFunction = (_, p1, p2) => p1 + p2;

Tests:

string
testCase.replace(testRegex, testReplaceText);
function
testCase.replace(testRegex, testReplaceFunction);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
string
function

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36

Browser/OS: Chrome 128 on Windows

View result in a separate tab

Test name	Executions per second
string	2651133.2 Ops/sec
function	2114403.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'd be happy to explain the benchmark and its options in detail.

**Benchmark Overview**

The provided JSON represents a JavaScript microbenchmark test case on MeasureThat.net. The benchmark compares two approaches for replacing a regular expression pattern with different replacement strings: a string literal (`testReplaceText`) versus a function that takes the matched groups as arguments (`testReplaceFunction`).

**Script Preparation Code**

The `Script Preparation Code` section of the JSON is used to set up the test environment and variables:
```javascript
var testCase = 'local'; // specifies the test case (in this case, "local")
var testRegex = /(o)c(a)/g; // defines the regular expression pattern to match
var testReplaceText = '$1$2'; // defines the string replacement
var testReplaceFunction = (_, p1, p2) => p1 + p2; // defines the function replacement
```
Here's what's happening:

* `testCase` is set to `'local'`, indicating that this is a local test case.
* `testRegex` defines the regular expression pattern to match: `o*c(a)` with the global (`g`) flag, which means it will find all occurrences in the string.
* `testReplaceText` defines the string replacement `$1$2`, where `$1` and `$2` are placeholders for the matched groups (in this case, `p1` and `p2`).
* `testReplaceFunction` defines a function that takes three arguments: `_` (the original match), `p1`, and `p2`. The function returns the concatenation of `p1` and `p2`.

**Benchmark Options**

The benchmark compares two options:

1. **String Literal Replacement**: Using `testReplaceText` as the replacement string.
	* Pros:
		+ Easy to understand and write.
		+ Fast execution, since it's a simple string concatenation.
	* Cons:
		+ Less flexible than a function-based approach.
2. **Function-Based Replacement**: Using `testReplaceFunction` as the replacement.
	* Pros:
		+ More flexible, as it allows for dynamic manipulation of the matched groups.
		+ Can potentially be faster than string literal replacement, since it avoids unnecessary string concatenation.

**Library Considerations**

In this benchmark, there is no explicit library mentioned. However, if we were to consider popular JavaScript libraries that might be used for regular expression replacements (e.g., `String.prototype.replace()`), the differences between these approaches would still apply.

**Special JS Feature/Syntax**

There are a few special features and syntax elements present in this benchmark:

* The global (`g`) flag on the regular expression pattern, which enables finding all occurrences in the string.
* The use of placeholders (`$1` and `$2`) in the replacement string, which will be replaced with the actual matched groups.
* The arrow function syntax (`=>`) for defining the `testReplaceFunction`.

**Alternatives**

If you wanted to write a similar benchmark, you could consider using other approaches:

* Using `String.prototype.replace()` method, comparing the performance of:
	+ String literal replacement (e.g., `str.replace(testRegex, testReplaceText)`)
	+ Function-based replacement (e.g., `str.replace(testRegex, function(match, p1, p2) { return p1 + p2; })`)
* Using a custom implementation for the replacement logic, comparing the performance of:
	+ String literal replacement
	+ Function-based replacement

Keep in mind that the specific details and options will depend on your use case and requirements.

Related benchmarks:

replacer string vs function 2 (version: 0)

Comparing performance of: string vs function

Created: 3 years ago by: Registered User

Jump to the latest result

string

function

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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