Benchmark: Array.from vs Spreadv2

Script Preparation code:

var fooSet = new Set();
for(var i=0;i<10000;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

Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36 Edg/145.0.0.0

Browser/OS: Chrome 145 on Windows

View result in a separate tab

Test name	Executions per second
Array.from	75371.4 Ops/sec
Spread	76018.4 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and explain what is being tested, compared, and their pros and cons.

**Benchmark Definition**

The benchmark measures the performance difference between two approaches to create an array from a set: `Array.from` (introduced in ECMAScript 2015) and the spread operator (`...`). The script preparation code creates a set of 10,000 integers using `Set`, and then attempts to convert it into an array using each of the two methods.

**Options Compared**

1. **`Array.from`**: Creates an array from an iterable (in this case, a set) by iterating over its elements.
2. **Spread Operator (`...`)**: Creates an array from an iterable by spreading its elements.

**Pros and Cons of Each Approach**

1. **`Array.from`**:
	* Pros:
		+ More explicit and readable code
		+ Can be more efficient in certain cases, as it allows for custom mapping functions
	* Cons:
		+ May incur additional overhead due to the iteration over the set's elements
2. **Spread Operator (`...`)**
	* Pros:
		+ More concise and expressive code
		+ Often faster, as it avoids the iteration step
	* Cons:
		+ Less explicit and potentially less readable code
		+ May not be compatible with all browsers or versions

**Library and Special JS Features**

Neither `Array.from` nor the spread operator relies on any specific libraries. However, `Array.from` does support custom mapping functions, which can be used to transform the elements of the set before creating the array.

**Test Case Considerations**

The test case uses a simple set of 10,000 integers to simulate a large dataset. This allows for a straightforward comparison between the two approaches. The use of `Set` and arrays ensures that the benchmark is measuring the performance difference in these specific data structures.

**Other Alternatives**

If you were to rewrite this benchmark using alternative methods, you might consider:

1. Using a custom array creation function, such as `new Int32Array(10000)`, which could provide additional insight into the performance characteristics of different array creation methods.
2. Utilizing other spread operators, like `JSON.parse(JSON.stringify(fooSet))`, to explore the performance implications of spreading objects versus arrays.
3. Measuring the performance of alternative set-to-array conversions, such as using `Array.prototype.concat()` or `Array.prototype.push()`, which might provide interesting insights into the trade-offs between different approaches.

Keep in mind that these alternatives would require significant changes to the benchmark definition and script preparation code.

Related benchmarks:

Array.from vs Spreadv2 (version: 1)

Comparing performance of: Array.from vs Spread

Created: 6 years ago by: Registered User

Jump to the latest result

Array.from

Spread

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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