Benchmark: spread test - MeasureThat.net

Tests:

test forEach
var array1 = []; [[1, 2, 3], [4, 5, 6], [7, 8, 9]].forEach(el => { el.forEach(e => { array1.push(e); }); });
test spread
var array1 = [[1, 2, 3], [4, 5, 6], [7, 8, 9]].reduce((array2, el) => { array2.push(...el); return array2; }, []);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
test forEach
test spread

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

I'll explain the benchmarking tests and their results in detail.

The provided JSON represents two microbenchmarks, both focusing on comparing different approaches for spreading elements from arrays or nested arrays into a new array.

**Benchmark 1: "test forEach"**

This test case uses a simple JavaScript function to iterate over an array of arrays using `forEach`. The goal is to measure the performance of this approach. Here's a breakdown of what's happening:

* An empty array `array1` is created.
* A 2D array `[ [1, 2, 3], [4, 5, 6], [7, 8, 9] ]` is defined, which contains three inner arrays.
* The `forEach` method is called on the outer array, iterating over each inner array. For each inner array, another `forEach` method is called on it, pushing its elements to `array1`.
* This test case is essentially measuring how fast this nested `forEach` approach can iterate and push elements into a new array.

**Benchmark 2: "test spread"**

This test case uses the spread operator (`...`) to flatten an array of arrays into a single array. The goal is to measure the performance of this approach. Here's what's happening:

* An empty array `array1` is created.
* A 2D array `[ [1, 2, 3], [4, 5, 6], [7, 8, 9] ]` is defined, similar to the previous test case.
* The `reduce` method with a callback function that uses the spread operator (`...`) is called on the outer array. This callback function takes an array and returns a new array containing all elements from both arrays (the original array and the one passed as an argument).
* This test case measures how fast this approach can flatten an array of arrays into a single array.

**Comparison of approaches**

The two tests are designed to compare the performance of these different approaches:

1. **Nested `forEach`**: This approach involves iterating over each inner array using another `forEach`, which may incur additional overhead due to function call overhead and potential caching issues.
2. **Spread operator (`...`)**: This approach is simpler, as it only requires calling the `reduce` method with a callback function that uses the spread operator.

**Pros and Cons**

* Nested `forEach`:
	+ Pros: Can be more explicit and easier to understand for complex iteration scenarios.
	+ Cons: May incur additional overhead due to function call overhead and potential caching issues.
* Spread operator (`...`):
	+ Pros: Simplifies the code, reduces overhead due to less function calls.
	+ Cons: Might require a deeper understanding of the `reduce` method and its behavior.

**Library**

In neither test case is a specific library used. The benchmark focuses on the built-in JavaScript features for iteration and array manipulation.

**Special JS feature/syntax**

There are no special JavaScript features or syntax mentioned in either test case.

**Alternatives**

If you were to rewrite these benchmarks, consider alternatives like:

1. Using `Array.prototype.flat()` instead of spread operator (`...`).
2. Comparing performance with other iteration methods, such as `for` loops or `map()`.
3. Including edge cases, like empty arrays or arrays with a single element.

Keep in mind that the benchmark is designed to compare different approaches for spreading elements from arrays or nested arrays into a new array, and these alternatives might not be directly related to this specific use case.

Related benchmarks:

spread test (version: 0)

Comparing performance of: test forEach vs test spread

Created: 8 years ago by: Guest

Jump to the latest result

test forEach

test 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):