Benchmark: empty an array in JavaScript - splice vs setting length 2

Tests:

Set length to zero
var size = 1000; var arr2 = []; for (var i = 0; i < size; i++){ arr2.push(i); } arr2.length = 0;
Splice
var size = 1000; var arr3 = []; for (var i = 0; i < size; i++){ arr3.push(i); } arr3.splice(0);
Set Array empty
var size = 1000; var arr3 = []; for (var i = 0; i < size; i++){ arr3.push(i); } arr3 = [];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Set length to zero
Splice
Set Array empty

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.4951.54 Safari/537.36

Browser/OS: Chrome 101 on Windows

View result in a separate tab

Test name	Executions per second
Set length to zero	183547.5 Ops/sec
Splice	174766.4 Ops/sec
Set Array empty	174820.6 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and its test cases.

**Benchmark Definition**

The website "MeasureThat.net" provides a JavaScript microbenchmarking tool that allows users to create and run tests for various JavaScript scenarios. The provided JSON represents a benchmark with three test cases:

* "empty an array in JavaScript - splice vs setting length 2"

This benchmark is testing the performance of two different approaches to empty an array in JavaScript:
	+ `splice`: Using the `splice` method to remove elements from the beginning of the array.
	+ Setting the length of the array to zero.

**Options Compared**

The three test cases are comparing the following options:

1. **Set length to zero**: This approach involves setting the length property of the array to zero, effectively removing all elements from the array.
2. **Splice**: This approach uses the `splice` method with an argument of 0 to remove the first element (and subsequent elements) from the array, leaving it empty.
3. **Set Array empty**: This approach involves reassigning the array to a new empty array using the assignment operator (`=`).

**Pros and Cons**

Here's a brief summary of the pros and cons of each approach:

1. **Set length to zero**:
	* Pros: Fast and efficient, as it only updates the length property.
	* Cons: May cause issues if the array is used for other purposes (e.g., iteration) before being emptied.
2. **Splice**:
	* Pros: Allows for flexibility in removing elements from the beginning of the array.
	* Cons: Can be slower than setting the length to zero, especially for large arrays.
3. **Set Array empty**:
	* Pros: Simple and straightforward approach.
	* Cons: May cause issues if the array is used for other purposes before being emptied.

**Library Usage**

None of the test cases explicitly use any libraries or external dependencies.

**Special JS Feature/Syntax**

There's no specific mention of special JavaScript features or syntax in the provided benchmark. However, it's worth noting that `splice` and array assignment (`=`) are standard JavaScript methods that don't rely on any advanced features.

**Other Alternatives**

If you're looking for alternative approaches to empty an array, consider:

1. Using a loop with the `pop` method: `for (var i = 0; i < size; i++) arr2.pop();`
2. Using a recursive function to remove elements from the beginning of the array
3. Using a library like Lodash or Ramda for more functional programming approaches

Keep in mind that these alternatives may not be as efficient as setting the length to zero or using `splice`, but they can provide different solutions depending on your specific use case.

**Device and Browser Considerations**

The benchmark results are provided for Chrome 101 running on a Windows Desktop. If you're interested in comparing performance across different browsers, devices, or operating systems, MeasureThat.net provides a range of test cases that cater to various scenarios.

Related benchmarks:

empty an array in JavaScript - splice vs setting length 2 (version: 0)

Based on question on http://stackoverflow.com/questions/1232040/how-do-i-empty-an-array-in-javascript

Comparing performance of: Set length to zero vs Splice vs Set Array empty

Created: 2 years ago by: Guest

Jump to the latest result

Set length to zero

Splice

Set Array empty

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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