Benchmark: JS filter vs splice +indexOf

Script Preparation code:

var arr = [];
var i = 0;

while (i <= 1E5) arr[i] = i++;

Tests:

Array.filter
const item = arr.filter(item => item !== 1E5);
Array.splice + Array.indexOf
const index = arr.splice(arr.indexOf(1E5), 1);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.filter
Array.splice + Array.indexOf

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/135.0.0.0 Safari/537.36

Browser/OS: Chrome 135 on Windows

View result in a separate tab

Test name	Executions per second
Array.filter	294.5 Ops/sec
Array.splice + Array.indexOf	1333574.8 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**What is being tested?**

The benchmark tests two different approaches to find and remove an item from an array in JavaScript:

1. `Array.filter()`: This method creates a new array with all elements that pass the test implemented by the provided function.
2. `Array.splice() + Array.indexOf()`: This approach uses the `indexOf()` method to find the index of the element to be removed, and then uses `splice()` to remove the element at that index.

**Options compared**

The two options being compared are:

* `Array.filter()`
* `Array.splice() + Array.indexOf()`

**Pros and Cons of each approach:**

* **`Array.filter()`**:
	+ Pros:
		- More concise and expressive code
		- Creates a new array, which can be more memory-efficient for large datasets
	+ Cons:
		- Can be slower than `splice()` + `indexOf()` for very large arrays (due to the overhead of creating a new array)
* **`Array.splice() + Array.indexOf()`**:
	+ Pros:
		- Faster execution time for large arrays (since it only modifies the original array)
	+ Cons:
		- Less concise and expressive code
		- Can be more memory-intensive since it modifies the original array

**Library used**

The `Array.filter()` method is a built-in JavaScript method, introduced in ECMAScript 5.

**Special JS feature or syntax**

None are mentioned in this benchmark.

**Other alternatives**

There are other methods to remove an item from an array in JavaScript, such as:

* Using the `map()` method with the callback function returning an empty value (e.g., `arr.map(item => item === 1E5 ? undefined : item)`), but this is less efficient than using `filter()`.
* Using a regular loop to iterate over the array and remove items (e.g., `for (var i = 0; i < arr.length; i++) { if (arr[i] === 1E5) arr.splice(i, 1); }`), but this is less concise than using `filter()` or `splice() + indexOf()`.

The benchmark uses the most common and efficient approach for each method, which is why we see `Array.filter()` and `Array.splice() + Array.indexOf()` being compared.

Related benchmarks:

JS filter vs splice +indexOf (version: 0)

JS find vs indexOf

Comparing performance of: Array.filter vs Array.splice + Array.indexOf

Created: 3 years ago by: Guest

Jump to the latest result

Array.filter

Array.splice + Array.indexOf

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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