Benchmark: array performance (vs slice, splice, length = 0)

Tests:

Splice
const testArray = [1, 2, 3]; const newTestArray = testArray.splice(0);
Slice
const testArray = [1, 2, 3]; const newTestArray = testArray.slice();
Length as 0
const testArray = [1, 2, 3]; testArray.length = 0; const newTestArray = testArray;

Historical Performance Data aggregated from 9 community runs

Desktop Results:

Chrome 9 runs

Slice

107.1M/s

Splice

43.7M/s

Length as 0

39.7M/s

Fastest: Slice (2.7x faster)

View exact numbers

✓ Slice: 107,100,552 ops/sec
• Splice: 43,731,548 ops/sec
• Length as 0: 39,653,276 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Splice
Slice
Length as 0

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/149.0.0.0 Safari/537.36

Browser/OS: Chrome 149 on Mac OS X 10.15.7

View result in a separate tab

Slice

176.8M/s

Splice

66.0M/s

Length as 0

54.5M/s

View exact numbers

Test name	Executions per second
✓ Slice	176,832,160 Ops/sec
Splice	65,962,444 Ops/sec
Length as 0	54,516,040 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in the provided benchmark.

The benchmark is designed to measure the performance of three different approaches when working with arrays in JavaScript:

1. **Splice**: This approach uses the `splice()` method to remove elements from the original array and create a new array with the removed elements.
2. **Slice**: This approach uses the `slice()` method to create a shallow copy of the original array, returning a new array object without modifying the original array.
3. **Length as 0**: This approach creates a new array by assigning the value `0` to the `length` property of the original array and then creating a new array from the modified original array.

**Comparison**

The three approaches are compared in terms of their performance, with the goal of determining which one is the fastest.

**Pros and Cons:**

* **Splice**:
	+ Pros: Efficient for removing elements from an array, as it modifies the original array and returns a new array.
	+ Cons: Can be slower than other approaches if the array is large, since it requires modifying the original array.
* **Slice**:
	+ Pros: Creates a shallow copy of the original array, which can be faster for large arrays, since it doesn't modify the original array.
	+ Cons: Returns a new array object without any references to the original array, so any changes made to the new array won't affect the original array.
* **Length as 0**:
	+ Pros: Can be faster than other approaches if the array is very small, since it doesn't require creating a new array or modifying the original array.
	+ Cons: Only works for arrays with a single element, and can lead to unexpected behavior if used incorrectly.

**Library/Functions Used**

* **splice()**: A built-in JavaScript function that modifies the original array and returns a new array with the removed elements.
* **slice()**: A built-in JavaScript function that creates a shallow copy of the original array, returning a new array object without modifying the original array.

**Special JS Feature/Syntax**

None mentioned in this specific benchmark. However, note that some JavaScript features or syntax may affect the performance of these approaches, such as:

* `const` keyword (used to declare variables and ensure immutability)
* `let` and `var` keywords (used for variable declarations with scoping)
* Array methods like `map()`, `filter()`, and `reduce()` (which can be used in place of `slice()` or other array manipulation methods)

**Alternatives**

Other approaches to compare arrays might include:

* Using `Array.prototype.slice.call()` to create a new array from the original array
* Using `Array.prototype.slice()` with an empty array as the second argument to avoid creating an unnecessary shallow copy
* Using `Array.prototype.slice()` with the `0` and `-1` indices to get a subset of the array without modifying the original array
* Using other libraries or frameworks that provide optimized array manipulation methods, such as Backbone.js or Lodash

array performance (vs slice, splice, length = 0) (version: 0)

Comparing performance of: `Splice vs Slice vs Length as 0`

Created: 2 years ago by: Guest

Go to the latest result

Splice

Slice

Length as 0

Historical Performance Data aggregated from 9 community runs

Desktop Results:

Chrome 9 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

array performance (vs slice, splice, length = 0) (version: 0)

Comparing performance of: Splice vs Slice vs Length as 0

Created: 2 years ago by: Guest

Go to the latest result

Splice

Slice

Length as 0

Historical Performance Data aggregated from 9 community runs

Desktop Results:

Chrome 9 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Related benchmarks

Comparing performance of: `Splice vs Slice vs Length as 0`