Benchmark: FindIndex + splice vs reverse filter

Script Preparation code:

var arr = new Array(15000);
arr.fill({ id: 0 });
arr = arr.map((el, idx) => el.id = idx);
var foo = Math.floor(Math.random() * 15000);

Tests:

FindIndex + splice
var index = arr.indexOf(foo); var newArr = arr.splice(index, 1);
filter
var index = arr.reverse().filter(el => el !== foo)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
FindIndex + splice
filter

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark definition and test cases.

**Benchmark Definition**

The benchmark is designed to compare two approaches for finding an element in an array:

1. **FindIndex + Splice**: This approach uses the `indexOf` method to find the index of the target element (`foo`) in the array, and then uses the `splice` method to remove the element at that index.
2. **Filter**: This approach uses the `reverse` method to reverse the order of the array, and then uses the `filter` method with a callback function to create a new array containing only the elements that do not match the target element (`foo`).

**Options Compared**

The benchmark compares two different approaches:

* FindIndex + Splice: Uses the `indexOf` method followed by the `splice` method.
* Filter: Uses the `reverse` method and then the `filter` method.

**Pros and Cons of Each Approach**

1. **FindIndex + Splice**:
	* Pros:
		+ Efficient use of memory, as it only creates a new array with the removed element.
		+ Can be faster for large arrays, since it avoids creating a new array.
	* Cons:
		+ Requires two method calls, which can be slower than a single method call.
		+ May cause performance issues if the `indexOf` method is slow or if the array is very large.
2. **Filter**:
	* Pros:
		+ Often faster for large arrays, since it only requires a single method call and can take advantage of the browser's built-in array optimization algorithms.
		+ Can be more concise and easier to read than the FindIndex + Splice approach.
	* Cons:
		+ Requires creating a new array with the filtered elements, which can use more memory.
		+ May not perform as well for small arrays or arrays that are mostly empty.

**Library**

The benchmark uses no external libraries. However, it does rely on the browser's built-in methods and features, such as `indexOf`, `splice`, `reverse`, and `filter`.

**Special JS Feature/Syntax**

There is no special JavaScript feature or syntax used in this benchmark. It only relies on standard JavaScript methods and features.

**Other Considerations**

* The benchmark creates a large array (`15000`) for testing, which can be slow to create.
* The `fill` method is used to populate the array with unique elements, which may not be necessary for all use cases.
* The `Math.random()` function is used to generate a random index (`foo`) for testing.

**Other Alternatives**

If you wanted to add additional alternatives to this benchmark, some possibilities could include:

* **Array.prototype.find()**: This method is similar to `indexOf`, but it returns the actual element instead of its index.
* **Array.prototype.some()**: This method tests whether at least one element in the array matches a certain condition, and can be used as an alternative to `filter`.
* **Using a different sorting algorithm**: Depending on the specific requirements of your use case, you might want to test different sorting algorithms (e.g. bubble sort, merge sort) instead of `reverse` + `filter`.

Note that these alternatives would require significant modifications to the benchmark code and may not be as straightforward or efficient as the original implementation.

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36 OPR/73.0.3856.329

Browser/OS: Opera 73 on Windows

View result in a separate tab

Test name	Executions per second
FindIndex + splice	3080595.5 Ops/sec
filter	9114859.0 Ops/sec

Related benchmarks:

FindIndex + splice vs reverse filter (version: 0)

Comparing performance of: FindIndex + splice vs filter

Created: 3 years ago by: Guest

Jump to the latest result

FindIndex + splice

filter

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):