Benchmark: Cloning array: Array.from vs spread corrected

Script Preparation code:

const array = window.array = []
for (let i = 1000; i; --i) array.push(i)

Tests:

Array.from
window.a = Array.from(array)
Spread
window.b = [...array]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.from
Spread

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

I'll break down the explanation into smaller sections to make it easier to understand.

**Benchmark Definition and Purpose**

The provided JSON represents a JavaScript microbenchmark named "Cloning array: Array.from vs spread corrected". The benchmark aims to compare the performance of two approaches for cloning an array:

1. `Array.from(array)`
2. `[...array]` (also known as the spread operator)

The purpose of this benchmark is to determine which method is faster and more efficient for creating a new copy of an array.

**Options Compared**

The two options being compared are:

1. `Array.from(array)`: This method creates a new array by iterating over the elements of the original array using the `from()` method.
2. `[...array]` (spread operator): This method uses the spread operator to create a new array by copying the elements of the original array.

**Pros and Cons**

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

1. `Array.from(array)`.
	* Pros:
		+ More explicit and readable code
		+ Can be used with other methods, such as `Map` and `Set`
	* Cons:
		+ May have higher overhead due to the iteration process
2. `[...array]` (spread operator).
	* Pros:
		+ Shorter and more concise code
		+ Often preferred for simple array cloning tasks
	* Cons:
		+ Less explicit and readable code, which can lead to confusion
		+ Not as widely supported in older browsers

**Library Usage**

There is no specific library used in this benchmark. However, the `Array.from()` method was introduced in ECMAScript 2015 (ES6) and became widely adopted.

**Special JS Features or Syntax**

This benchmark does not use any special JavaScript features or syntax beyond what's required for array cloning.

**Other Alternatives**

If you're interested in exploring other approaches for array cloning, here are a few alternatives:

1. `slice()`: This method creates a shallow copy of an array by returning a new array object with references to the same elements.
2. `concat()`: This method creates a new array by concatenating two or more arrays together.
3. Using a library like Lodash's `clone()` function, which can create a deep copy of an array.

Keep in mind that these alternatives may have different performance characteristics and use cases compared to the `Array.from()` and spread operator methods being benchmarked here.

I hope this explanation helps you understand the test case!

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.116 Safari/537.36

Browser/OS: Chrome 80 on Mac OS X 10.15.1

View result in a separate tab

Test name	Executions per second
Array.from	1239716.8 Ops/sec
Spread	1404474.2 Ops/sec

Related benchmarks:

Cloning array: Array.from vs spread corrected (version: 0)

Comparing performance of: Array.from vs Spread

Created: 4 years ago by: Guest

Jump to the latest result

Array.from

Spread

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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