Benchmark: concat.apply short form new array vs flat

Script Preparation code:

var array1 = Array(400).fill().map(() => Math.round(Math.random() * 40));
var array2 = Array(400).fill().map(() => Math.round(Math.random() * 40));
var array3 = Array(400).fill().map(() => Math.round(Math.random() * 40));
var array4 = Array(400).fill().map(() => Math.round(Math.random() * 40));
var array5 = Array(400).fill().map(() => Math.round(Math.random() * 40));

var allArrays = [array1, array2, array3, array4, array5];

Tests:

concat.apply
var others = [].concat.apply([], allArrays);
flat
var others = allArrays.flat()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
concat.apply
flat

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided JSON data and explain what is being tested, compared, and the pros/cons of different approaches.

**Benchmark Definition:**

The benchmark measures two approaches for concatenating arrays:

1. `Array.prototype.concat.apply`: This method applies the `concat` function to an array-like object using the `apply` method.
2. `.flat()`: This method returns a new array with all subarrays nested at the same level as the original array.

**Script Preparation Code:**

The script generates five arrays of 400 elements each, filled with random integers between 0 and 40. These arrays are stored in variables `array1` to `array5`. The `allArrays` variable is an array containing these five arrays.

**Html Preparation Code:**

This field is empty, indicating that no HTML preparation code is required for this benchmark.

**Individual Test Cases:**

There are two test cases:

1. **concat.apply**: This test case applies the `concat.apply` method to concatenate all five arrays into a single array using the `allArrays` variable.
2. **flat**: This test case uses the `.flat()` method to concatenate all five arrays into a single array.

**Pros and Cons:**

* **concat.apply**:
	+ Pros:
		- Can be used with any array-like object.
		- Allows for more control over the concatenation process (e.g., specifying an initial value).
	+ Cons:
		- Can be slower due to the `apply` method's overhead.
		- May require more memory to store the intermediate results.
* `.flat()`: 
	+ Pros:
		- More concise and readable syntax.
		- Faster execution speed (optimized for modern JavaScript engines).
	+ Cons:
		- Limited control over the concatenation process.

**Library Usage:**

The `concat.apply` method uses the built-in `Array.prototype.concat()` function, which is a part of the JavaScript standard library. The `.flat()` method uses the native `Array.prototype.flat()` function, also part of the JavaScript standard library.

**Special JS Features/Syntax:**

None mentioned in this benchmark definition.

**Other Alternatives:**

If you're looking for alternative approaches to concatenating arrays, consider using:

1. **`.reduce()`**: This method can be used to concatenate arrays by reducing them into a single array.
2. **`Array.prototype.reduceRight()``: Similar to `.reduce()`, but starts from the right end of the array.
3. **`.concat()`** and `array.push()`: Concatenating arrays using the `push()` method, followed by concatenating the resulting arrays.

Keep in mind that these alternatives may have different performance characteristics or requirements for specific use cases.

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.4951.64 Safari/537.36

Browser/OS: Chrome 101 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
concat.apply	1479548.5 Ops/sec
flat	7156.7 Ops/sec

Related benchmarks:

concat.apply short form new array vs flat (version: 0)

Comparing Array.prototype.concat.apply short form with empty array vs flat

Comparing performance of: concat.apply vs flat

Created: 2 years ago by: Guest

Jump to the latest result

concat.apply

flat

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):