Benchmark: Bench flat map vs spread reduceqwe

Script Preparation code:

var arr = Array(10_000).fill([0,0,0])

Tests:

spread
[...arr]
flatmap
arr.flatMap((item) => { return item; });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread
flatmap

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36

Browser/OS: Chrome 122 on Windows

View result in a separate tab

Test name	Executions per second
spread	97922.6 Ops/sec
flatmap	2024.3 Ops/sec

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

LLMs can make mistakes. Check important info.

I'd be happy to help explain what's being tested in this benchmark.

**What is tested?**

The provided benchmark measures the performance difference between using the spread operator (`...`) and `flatMap()` methods on an array of arrays (`arr`). The test case consists of two individual tests: "spread" and "flatmap".

**Options compared**

In the first test ("spread"), the benchmark runs a loop that iterates over each inner array in `arr` using the spread operator (`...`), like this:
```javascript
arr.flatMap((item) => {
  return item;
});
```
This is equivalent to using a for-of loop or Array.prototype.forEach() with a callback function.

In the second test ("flatmap"), the benchmark runs a similar loop that iterates over each inner array in `arr` using the `flatMap()` method, like this:
```javascript
arr.flatMap((item) => {
  return item;
});
```
**Pros and cons of each approach**

* **Spread operator (`...`)**: This approach is concise and readable, as it eliminates the need for a loop or callback function. However, it may incur additional overhead due to the creation of new arrays.
* `flatMap()` method: This approach is also concise and readable, but it uses built-in array method that may be optimized by the engine. Additionally, some older browsers may not support this method.

**Library and syntax**

In both tests, no external libraries are used. The JavaScript syntax itself is being compared.

**Special JS feature or syntax**

There is no special JavaScript feature or syntax being tested here, as it's just a straightforward comparison of two array methods.

**Other alternatives**

If you wanted to test this benchmark with alternative approaches, some options could be:

* Using a traditional for-of loop:
```javascript
for (const item of arr) {
  result.push(...item);
}
```
* Using Array.prototype.forEach() with a callback function:
```javascript
arr.forEach((item) => {
  result = result.concat(item);
});
```
Keep in mind that these alternatives might introduce additional overhead or changes to the performance characteristics.

**Benchmark preparation code**

The provided benchmark preparation code creates an array `arr` with 10,000 elements, each containing three zeros. This ensures a large enough dataset for meaningful performance comparisons.

**Individual test cases**

Each individual test case consists of a single "Benchmark Definition" JSON object that represents the input data for the test. The first test ("spread") and second test ("flatmap") both use the same `arr` array as their input, but with different implementation details (i.e., using the spread operator vs. `flatMap()` method).

**Latest benchmark result**

The provided benchmark result shows the execution counts per second for each test case, running on Chrome 122 on a desktop device. The results will likely vary depending on the specific hardware and engine configuration used to run the benchmarks.

Related benchmarks:

Bench flat map vs spread reduceqwe (version: 0)

Comparing performance of: spread vs flatmap

Created: 2 years ago by: Guest

Jump to the latest result

spread

flatmap

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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