Benchmark: sam's non-mutating array remove element: spread and slice vs slice and splice vs filter

Script Preparation code:

var array = Array.from({ length: 2000 }).map((val, i) => i);

Tests:

spread
var output = [...array.slice(0, 38), ...array.slice(39)]
splice
var output = array.slice().splice(38, 1)
filter
var output = array.filter((el, i) => i !== 38)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread
splice
filter

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided benchmark measures the performance of three different approaches to remove an element from a non-mutating array in JavaScript: using `slice()` and `splice()`, using `filter()`, and using the spread operator (`...`).

**Approach 1: Using `slice()` and `splice()`**

This approach creates two new arrays: one by slicing the original array up to the index of the element to be removed, and another by slicing it from after the element to be removed. It then concatenates these two arrays using the spread operator (`...`).

**Pros:**

* This approach is generally efficient because it only requires creating a few new arrays.
* It avoids modifying the original array.

**Cons:**

* Creating multiple arrays can lead to increased memory allocation and deallocation, which can be slow for large arrays.
* The use of `slice()` and `splice()` may incur additional overhead due to their mutator nature.

**Approach 2: Using `filter()`**

This approach uses the `filter()` method to create a new array that includes all elements except the one at the specified index.

**Pros:**

* This approach is efficient because it only requires creating a single new array.
* The use of `filter()` does not modify the original array.

**Cons:**

* Creating a large array with many elements can lead to increased memory allocation and deallocation, which can be slow.
* The use of `filter()` may incur additional overhead due to its iterator nature.

**Approach 3: Using the Spread Operator (`...`)**

This approach uses the spread operator (`...`) to create a new array that includes all elements from the original array except the one at the specified index.

**Pros:**

* This approach is efficient because it only requires creating a single new array.
* The use of the spread operator can be faster than using `slice()` or `filter()` because it avoids the overhead of iterator creation.

**Cons:**

* Creating a large array with many elements can lead to increased memory allocation and deallocation, which can be slow.
* Some older JavaScript engines may not support the spread operator or have limited performance optimizations for it.

**Library Usage**

The benchmark does not use any external libraries beyond the standard JavaScript library.

**Special JS Features or Syntax**

There are no special JS features or syntax used in this benchmark. However, it's worth noting that the benchmark uses modern JavaScript features such as template literals (`Array.from()`) and spread operator (`...`), which may require support for ECMAScript 2015 (ES6) or later.

**Alternative Approaches**

Other approaches to remove an element from a non-mutating array in JavaScript include:

* Using `map()` with a function that returns the desired output
* Using `reduce()` with a callback function that updates the accumulator
* Using a custom loop with indexing and array manipulation

However, these approaches may have different performance characteristics depending on the specific use case and JavaScript engine.

Latest run results:

Run details: (Test run date: 5 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36

Browser/OS: Chrome 65 on Linux

View result in a separate tab

Test name	Executions per second
spread	8490.8 Ops/sec
splice	293396.4 Ops/sec
filter	41699.4 Ops/sec

Related benchmarks:

sam's non-mutating array remove element: spread and slice vs slice and splice vs filter (version: 0)

Comparing performance of: spread vs splice vs filter

Created: 5 years ago by: Registered User

Jump to the latest result

spread

splice

filter

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):