Benchmark: FlatMap method vs for loop

Script Preparation code:

var arr = Array(10_000).fill(0);

Tests:

flatMap
arr.flatMap(x => [x, x * 2]);
for loop
const n = arr.length; const acc = new Array(n * 2); for (let i = 0; i < n; i++){ const x = arr[i]; acc[i * 2] = x; acc[i * 2 + 1] = x * 2; }

Historical Performance Data aggregated from 87 community runs

Desktop Results:

Chrome 66 runs

for loop

25K/s

flatMap

4K/s

Fastest: for loop (6.8x faster)

View exact numbers

✓ for loop: 25,078 ops/sec
• flatMap: 3,680 ops/sec

Firefox 16 runs

for loop

20K/s

flatMap

4K/s

Fastest: for loop (5.6x faster)

View exact numbers

✓ for loop: 20,165 ops/sec
• flatMap: 3,590 ops/sec

Mobile Results:

Safari 5 runs

flatMap

12K/s

for loop

3K/s

Fastest: flatMap (3.7x faster)

View exact numbers

✓ flatMap: 11,624 ops/sec
• for loop: 3,166 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
flatMap
for loop

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/149.0.0.0 Safari/537.36

Browser/OS: Chrome 149 on Windows

View result in a separate tab

for loop

45K/s

flatMap

5K/s

View exact numbers

Test name	Executions per second
✓ for loop	44,936 Ops/sec
flatMap	4,581 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks.

**What is being tested?**

The provided JSON represents a benchmark test case on MeasureThat.net, which compares the performance of two approaches: using the `flatMap()` method and a traditional `for` loop. The test aims to determine which approach is faster for an array transformation task.

**Options compared:**

1. **flatMap()**: A method introduced in ECMAScript 2019 that flattens arrays by applying a provided function to each element.
2. **Traditional for loop**: A common control structure used to iterate over arrays and perform operations on their elements.

**Pros and cons of each approach:**

1. **flatMap():**
	* Pros:
		+ Concise and expressive syntax.
		+ Encapsulates the iteration logic, making it easier to write and maintain code.
	* Cons:
		+ May incur overhead due to function call and array manipulation.
2. **Traditional for loop:**
	* Pros:
		+ Control over iteration flow and element access.
		+ Can be more efficient in certain cases, as it avoids the overhead of function calls and array manipulation.
	* Cons:
		+ More verbose syntax, making code harder to read and write.

**Library used:**

In this test case, no specific library is explicitly mentioned. However, the `flatMap()` method is a part of the ECMAScript standard, which means it's built into modern JavaScript engines.

**Special JS feature or syntax:**

None are mentioned in this test case.

**Other considerations:**

When choosing between these two approaches, consider the following factors:

* Readability and maintainability: If code readability is crucial, `flatMap()` might be a better choice due to its concise syntax.
* Performance: In hot-path scenarios where every cycle counts, the traditional `for` loop might be preferred for its potential efficiency gains.

**Alternatives:**

For this specific task, other approaches could include:

1. Using `forEach()`: While not as efficient as `flatMap()` in terms of performance, `forEach()` can still provide a concise way to perform array transformations.
2. Utilizing `reduce()`: Another array method that can be used for transformation tasks, but might require more boilerplate code compared to `flatMap()`.
3. Implementing custom iteration logic using bitwise operations or bit-manipulation techniques (for low-level optimization).

Keep in mind that the choice of approach depends on the specific use case and personal preference. MeasureThat.net's benchmarking framework is designed to provide a fair comparison between different approaches, allowing users to make informed decisions about their code optimizations.

FlatMap method vs for loop (version: 0)

Compare the performance of for loop vs flatMap method

Comparing performance of: `flatMap vs for loop`

Created: 4 years ago by: Registered User

Go to the latest result

flatMap

for loop

Historical Performance Data aggregated from 87 community runs

Desktop Results:

Chrome 66 runs

Firefox 16 runs

Mobile Results:

Safari 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

FlatMap method vs for loop (version: 0)

Compare the performance of for loop vs flatMap method

Comparing performance of: flatMap vs for loop

Created: 4 years ago by: Registered User

Go to the latest result

flatMap

for loop

Historical Performance Data aggregated from 87 community runs

Desktop Results:

Chrome 66 runs

Firefox 16 runs

Mobile Results:

Safari 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Related benchmarks

Comparing performance of: `flatMap vs for loop`