Benchmark: hb-2365-test - MeasureThat.net

Script Preparation code:

const arr = Array(500).fill(null);
var parents = arr.map(() => {
    return {
        children: arr.map((value, index) => ({value, selected: index % 2})),
    };
});

Tests:

Not optimized
let out = []; parents.forEach(parent => { const selected = parent.children.filter(child => child.selected).map(child => child.value); out = [...out, ...selected]; });
Optimized
const out = []; parents.forEach(parent => { parent.children.forEach(child => child.selected && out.push(child.value)); });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Not optimized
Optimized

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

The benchmark is designed to test the performance of two different approaches for processing an array of objects in JavaScript. The test data consists of 500 null values, each wrapped in an object with a "children" property that contains an array of the same null values. The goal is to flatten this nested structure into a single array.

**Benchmark Definitions**

There are two benchmark definitions:

1. **Not optimized**: This approach uses the `filter()` and `map()` methods to iterate over each parent's children, filtering out unselected children.
2. **Optimized**: This approach also iterates over the children of each parent, but it uses a single loop with an early return condition (`child.selected`) instead of using `filter()`.

**Options Compared**

The two approaches differ in how they process the nested array:

* **Not optimized**: Uses `filter()` and `map()` to iterate over each parent's children.
* **Optimized**: Uses a single loop with an early return condition (`child.selected`).

**Pros and Cons**

Here are some pros and cons of each approach:

* **Not optimized**:
	+ Pros: More explicit, easier to understand.
	+ Cons: Can be slower due to the use of `filter()` and `map()`.
* **Optimized**:
	+ Pros: Faster since it uses a single loop with an early return condition.
	+ Cons: Less readable due to the use of a single loop.

**Library/Functionality Used**

There is no specific library used in these benchmark definitions. However, the `Array.prototype.map()` method is a built-in JavaScript function that applies a transformation to each element in an array.

**Special JS Feature/Syntax**

Neither of the benchmark definitions uses any special JavaScript features or syntax. The test code only relies on standard JavaScript methods and operations.

**Other Alternatives**

If you're interested in exploring alternative approaches, here are a few:

1. Using `reduce()` instead of `map()`.
2. Using `forEach()` with an early return condition.
3. Implementing a custom loop that iterates over the children of each parent.

Keep in mind that these alternatives might not necessarily improve performance or readability, and some might even be slower than the optimized approach used in the benchmark.

Latest run results:

Run details: (Test run date: 5 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.103 Safari/537.36

Browser/OS: Chrome 73 on Linux

View result in a separate tab

Test name	Executions per second
Not optimized	3.0 Ops/sec
Optimized	306.0 Ops/sec

Related benchmarks:

hb-2365-test (version: 0)

Comparing performance of: Not optimized vs Optimized

Created: 5 years ago by: Guest

Jump to the latest result

Not optimized

Optimized

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):