Benchmark: Array filtering: (splice + predefined index) vs (filter) - big array

Script Preparation code:

var arr1 = new Array(10000).fill(0);
var arr2 = new Array(10000).fill(0);
var indexesToDelete = [3, 10, 40, 90, 150, 500, 1000, 1500, 2000, 2500, 3000, 4000, 5000, 6000, 7000, 8000, 9000];

indexesToDelete.forEach(index => {
	arr1[index] = 1;
  	arr2[index] = 1;
});

Tests:

splice
indexesToDelete.forEach(index => { arr1.splice(index, 1); });
filter
const newArr = arr2.filter(value => value !== 1);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
splice
filter

Fastest: N/A

Slowest: N/A

Latest run results:

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

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

**Benchmark Definition**

The benchmark is defined as an array filtering operation, where we need to delete specific elements from an array using two different approaches:

1. `splice`: This method modifies the original array by removing a specified number of elements at a given index.
2. `filter`: This method creates a new array with all elements that pass a test implemented by a provided function.

**Options Compared**

The benchmark compares the performance of these two approaches on a large array (10,000 elements) and 14 specific indexes that need to be deleted.

**Pros and Cons**

* **splice**:
	+ Pros: Modifies the original array in-place, which can lead to better performance for certain use cases.
	+ Cons: Can be slower than `filter` for very large arrays, as it requires shifting all elements after the removed index.
* **filter**:
	+ Pros: Creates a new array without modifying the original one, which can be faster and more memory-efficient for very large datasets.
	+ Cons: Requires extra memory to store the new array, which can be a limitation.

**Library**

None of the benchmark code uses any external libraries. The `Array.prototype.splice()` method is a built-in JavaScript function.

**Special JS Feature or Syntax**

The benchmark does not use any special JavaScript features or syntax that would require explanation beyond the scope of this answer.

**Other Alternatives**

If you need to delete specific elements from an array, you could also consider using:

* `slice()`: Similar to `splice`, but returns a new array with the removed elements.
* `indexOf()` and `splice()`: These methods can be used together to remove multiple elements at once.
* `reduce()`: This method can be used to create a new array by applying a reduction function to each element.

Keep in mind that the performance differences between these approaches may vary depending on the specific use case and array size.

**Benchmark Preparation Code**

The script preparation code creates two large arrays (`arr1` and `arr2`) filled with zeros, and defines an array of indexes to delete from each array. It then iterates through this array and sets each element at the specified index to 1 using both the `splice()` and `filter()` methods.

**Individual Test Cases**

The benchmark has two individual test cases:

* "splice"
* "filter"

These test cases execute the corresponding benchmark definition code and measure their performance.

Related benchmarks:

Array filtering: (splice + predefined index) vs (filter) - big array (version: 1)

Comparing performance of: splice vs filter

Created: 3 years ago by: Registered User

Jump to the latest result

splice

filter

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):