Benchmark: Array.from vs Spread - Huge dataset

Tests:

Array.from
var fooSet = new Set(); for(var i=0;i<1000000;i++) { fooSet.add(i); } var other = Array.from(fooSet);
Spread
var fooSet = new Set(); for(var i=0;i<1000000;i++) { fooSet.add(i); } 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

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Let's dive into explaining the provided JavaScript microbenchmark, which compares two approaches for converting a large dataset from a Set to an Array.

**What is being tested?**

The benchmark tests the performance of two methods:

1. `Array.from()`: A built-in method that creates a new array from an iterable (like a Set) by iterating over it and creating an array with each value.
2. Spread syntax (`...fooSet`): This approach uses the spread operator to create a new array from the values in the Set.

**Options compared**

The benchmark compares the performance of these two approaches on a large dataset of 1,000,000 values.

**Pros and Cons:**

* `Array.from()`: Pros:
	+ More explicit and readable code.
	+ Built-in method, which is likely to be optimized by the JavaScript engine.
	+ Works with any iterable, not just Sets.
Cons:
	+ May have higher overhead due to the creation of an intermediate array during iteration.
* Spread syntax (`...fooSet`): Pros:
	+ More concise and efficient code.
	+ Can avoid creating an intermediate array during iteration.
Cons:
	+ Less readable code, especially for large datasets or complex iterables.
	+ Only works with Sets.

**Library/External dependencies:**

There are no external libraries used in this benchmark. The `Set` data structure is a built-in JavaScript object.

**Special JS features/syntax:**

The benchmark uses the spread operator (`...`) which is a relatively new feature introduced in ECMAScript 2015 (ES6). It allows for more concise array creation and is widely supported in modern browsers.

**Other considerations:**

* The benchmark runs on a desktop platform with Chrome 87 browser, which may affect the results.
* The dataset size of 1,000,000 values is considered "huge" in the context of JavaScript benchmarks, but it's still relatively small compared to some other benchmark datasets.
* It's worth noting that the performance difference between these two approaches may not be significant for most use cases, and readability and maintainability should take precedence over micro-optimizations.

**Alternatives:**

If you need to convert a large dataset from a Set to an Array in JavaScript, you could consider using other methods, such as:

* Using `Array.prototype.forEach()` with `push()`: `new Array(fooSet.size).fill().forEach((_, i) => fooSet.get(i));`
* Using `reduce()`: `fooSet.reduce((acc, curr) => [...acc, curr], [])`

Keep in mind that these alternatives may have different performance characteristics and trade-offs compared to the spread syntax and `Array.from()` methods.

Related benchmarks:

Array.from vs Spread - Huge dataset (version: 0)

Comparing performance of: Array.from vs Spread

Created: 5 years ago by: Guest

Jump to the latest result

Array.from

Spread

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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