Benchmark: Array.from vs Spread Test

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:

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

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Let's break down the benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark is comparing two approaches for converting a Set object to an Array:

1. `Array.from()` method
2. Spread operator (`...`) syntax

Both methods are used to convert a Set object to an Array, but they differ in their implementation details and performance characteristics.

**Options Compared**

* `Array.from()`: This method creates a new Array instance from the elements of a given iterable (in this case, a Set). It iterates over the Set's elements and pushes them onto the new Array.
* Spread operator (`...`): This syntax creates a new Array instance by spreading the elements of the Set into an array.

**Pros and Cons**

* `Array.from()`:
	+ Pros: More explicit and readable, as it clearly specifies the intention to convert the Set to an Array. It also allows for additional parameters to customize the creation process.
	+ Cons: May incur overhead due to the iteration over the Set's elements.
* Spread operator (`...`):
	+ Pros: Concise and expressive syntax, allowing developers to quickly convert a Set to an Array without explicit loops.
	+ Cons: Less readable and less explicit than `Array.from()`, as it relies on the developer's familiarity with array destructuring.

**Library**

There is no specific library used in this benchmark. The Set object and Array instances are part of the JavaScript Standard Library.

**Special JS Feature or Syntax**

The spread operator (`...`) syntax is a newer feature introduced in ECMAScript 2018 (ES2018). It's also known as "rest/spread syntax" or "array destructuring." This syntax allows developers to extract elements from an array and use them in other contexts, such as creating new arrays.

**Benchmark Preparation Code**

The preparation code for each test case is minimal:

* `Array.from()` test: Creates a new Set instance with 1 million elements and adds them using the `add()` method.
* Spread operator (`...`) test: Creates a new Set instance with 1 million elements and adds them using the `add()` method.

The preparation code ensures that both methods are executed under identical conditions, allowing for fair comparisons of their performance characteristics.

**Other Alternatives**

Alternative approaches to convert a Set object to an Array include:

* Using the `slice()` method: `Array.prototype.slice.call(mySet)`
* Using the `map()` method: `mySet.map(x => x)`
* Using the `forEach()` method with `Array.prototype.push()`: `var arr = []; mySet.forEach((x) => { arr.push(x); });`

However, these alternatives may incur higher overhead or be less efficient than using `Array.from()` or the spread operator.

**Benchmark Result**

The latest benchmark results show:

* `Array.from()`: 9.180550575256348 executions per second
* Spread operator (`...`): 8.792695045471191 executions per second

These results indicate that `Array.from()` is slightly faster than the spread operator syntax in this specific benchmark. However, the difference may be negligible for most use cases, and the choice between these approaches ultimately depends on personal preference and coding style.

Related benchmarks:

Array.from vs Spread Test (version: 0)

Comparing performance of: Array.from vs Spread

Created: 3 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):