Benchmark: Spread vs for with push

Tests:

For with push
a = [1,2,3,4,5,6,7,8,9,10] b = [] a.forEach(a1 => b.push(a1))
Spread with push
a = [1,2,3,4,5,6] b = [] b.push(...a)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
For with push
Spread with push

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):

LLMs can make mistakes. Check important info.

I'd be happy to explain the benchmark and its options.

**What is tested?**

The provided JSON represents a JavaScript microbenchmark that tests two approaches for adding elements to an empty array (`[]`): using `forEach` with `push` or using spread operator (`...`) with `push`.

**Options compared:**

There are two main options being compared:

1. **Using `forEach` with `push`:**
	* This approach iterates over the elements of the original array (`a`) and pushes each element to the target array (`b`).
	* The advantage is that it allows for more control over the iteration process, but may incur additional overhead due to function calls.
2. **Using spread operator (`...`) with `push`:**
	* This approach uses the spread operator to create a new array from the elements of `a`, and then pushes this new array to `b`.
	* The advantage is that it creates a new array, which can lead to performance benefits due to caching and vectorization optimizations in modern JavaScript engines.

**Pros and Cons:**

* **For with push:**
	+ Pros:
		- More control over iteration process
	+ Cons:
		- May incur additional overhead due to function calls
		- Can be slower due to the need for explicit loop control
* **Spread with push:**
	+ Pros:
		- Creates a new array, which can lead to performance benefits
	+ Cons:
		- Requires the use of the spread operator, which may not be widely supported in older browsers
		- Can create temporary objects and arrays, which may not be desirable for memory-constrained applications

**Library usage:**

None of the provided benchmark code uses any external libraries.

**Special JS features or syntax:**

There are no special JavaScript features or syntax used in this benchmark. The focus is on comparing two basic array manipulation approaches.

**Other alternatives:**

If you were to design a more comprehensive benchmark, you might consider additional scenarios, such as:

* Using `for` loops instead of `forEach`
* Adding elements to an existing array instead of creating a new one
* Using different data structures, such as objects or sets
* Including browser-specific optimizations, such as WebAssembly or SIMD

Keep in mind that the design of a benchmark should prioritize relevance and accuracy over comprehensiveness. The goal is to accurately compare different approaches and highlight their performance characteristics.

Latest run results:

Run details: (Test run date: 6 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36

Browser/OS: Chrome 67 on Mac OS X 10.13.3

View result in a separate tab

Test name	Executions per second
For with push	273618.2 Ops/sec
Spread with push	799220.1 Ops/sec

Related benchmarks:

Spread vs for with push (version: 0)

Comparing performance of: For with push vs Spread with push

Created: 6 years ago by: Guest

Jump to the latest result

For with push

Spread with push

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):