Benchmark: Array.from vs Spread (1000 numbers)

Script Preparation code:

var fooSet = new Set();
for(var i=0;i<1000;i++) {
  fooSet.add(i);
}

Tests:

Array.from
var other = Array.from(fooSet);
Spread
var other = [...fooSet];

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 Sumamry (model llama3.2:3b, generated 3 days ago):

LLMs can make mistakes. Check important info.

Measuring the performance of different approaches to convert an iterable to an array in JavaScript is a fascinating benchmark.

**What's being tested:**

In this benchmark, we're comparing two ways to create an array from an iterable:

1. `Array.from()`
2. The spread operator (`...`)

The test creates a large set of numbers (1000 elements) and then uses these sets to convert them to arrays using the above two methods.

**Options being compared:**

* `Array.from()`: A method that creates a new array from an iterable (e.g., an object, array, or iterator).
	+ Pros:
		- Allows for more flexibility in creating arrays from various iterables.
		- Can be used with iterators and other advanced iterables.
	+ Cons:
		- May incur additional overhead due to the method's complexity.
* The spread operator (`...`): A syntax that creates a new array by iterating over an iterable and adding its elements to a new array.
	+ Pros:
		- Typically faster than `Array.from()` since it doesn't require a separate method call.
		- More concise and expressive code.
	+ Cons:
		- Limited to creating arrays from iterables that implement the iterator protocol (e.g., objects with `[[Prototype]]` set to `{}`).
		- May not work as expected with some advanced iterators.

**Pros and cons of each approach:**

* `Array.from()`: Generally faster for small arrays, but may have higher overhead for large arrays due to the method's complexity. However, it provides more flexibility in creating arrays from various iterables.
* The spread operator (`...`): Typically faster and more concise than `Array.from()`, but may not work as expected with some advanced iterators or larger arrays.

**Library usage:**

In this benchmark, we're using none of the built-in JavaScript libraries. However, if you were to extend this benchmark to include other libraries, some possibilities might include:

* Lodash's `from` function (not actually used in this example)
* Ramda's `from` function
* Other utility libraries that provide array creation functions

**Special JS feature or syntax:**

None mentioned in this specific benchmark. However, the use of iterators and advanced iterables is an important consideration when working with modern JavaScript.

**Other alternatives:**

If you wanted to extend this benchmark to compare other approaches to creating arrays from iterables, some possibilities might include:

* `Array.prototype.slice()` or `Array.prototype.concat()`
* Using a library like Immutable.js for immutable array creation
* Using a library like RxJS for reactive array creation

Keep in mind that the performance differences between these alternatives may be significant, and the choice of approach will depend on the specific use case and requirements.

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/117.0.0.0 Safari/537.36

Browser/OS: Chrome 117 on Windows

View result in a separate tab

Test name	Executions per second
Array.from	438747.1 Ops/sec
Spread	471933.3 Ops/sec

Related benchmarks:

Array.from vs Spread (1000 numbers) (version: 0)

Comparing performance of: Array.from vs Spread

Created: one year 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 Sumamry (model llama3.2:3b, generated 3 days ago):