Benchmark: Array flat vs isArray check

Script Preparation code:

var noarr = 5555
var array = [1,2,3,4,5]
var array2 = [[1,2],[3,4],[5,6]]

Tests:

Array.flat
const f1 = [noarr].flat(1) const f2 = [array].flat(1) const f3 = [array2].flat(1)
isArray check
const n1 = Array.isArray(noarr) ? noarr : [noarr] const n2 = Array.isArray(array) ? array : [array] const n3 = Array.isArray(array2) ? array2 : [array2]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.flat
isArray check

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36

Browser/OS: Chrome 114 on Windows

View result in a separate tab

Test name	Executions per second
Array.flat	76484.1 Ops/sec
isArray check	230601.9 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

The benchmark compares two approaches:

1. `Array.flat()`: This method is used to flatten an array of arrays into a single array.
2. `isArray check` (a shorthand way to check if an element is an array using `Array.isArray()`)

**Options Compared**

The benchmark tests the performance of both options under the same input data.

**Pros and Cons of Each Approach:**

1. `Array.flat()`
	* Pros:
		+ More concise and readable code.
		+ Can handle nested arrays of arbitrary depth.
		+ Often faster due to the built-in implementation.
	* Cons:
		+ May not be suitable for very large input sizes (due to potential stack overflow).
		+ Can be slower than `isArray check` in some cases, especially when dealing with shallow arrays.
2. `isArray check`
	* Pros:
		+ Suitable for all array sizes and depths.
		+ Often faster due to the explicit type checking.
	* Cons:
		+ Requires an additional function call (`Array.isArray()`).
		+ Code can be less readable due to the use of a conditional statement.

**Library/Functionality:**

In this benchmark, no external library is used. The `Array.flat()` and `Array.isArray()` functions are part of the JavaScript standard library.

**Special JS Feature/Syntax:**

No special JavaScript feature or syntax is being tested in this benchmark. Both options rely on basic array operations.

**Other Considerations:**

* In real-world scenarios, you might need to consider additional factors like error handling, edge cases, and performance optimizations.
* The choice between `Array.flat()` and `isArray check` ultimately depends on the specific requirements of your use case.

**Alternative Approaches:**

For more complex array manipulation tasks or performance-critical code paths, other approaches may be worth considering:

1. Using a library like Lodash (`_.flatten()`) for more comprehensive array flattening capabilities.
2. Implementing custom logic using loops and conditional statements to avoid relying on built-in methods like `Array.flat()` or `Array.isArray()`.
3. Considering alternative data structures, such as Typed Arrays or typed arrays with `Uint8Array` or other specific types.

Keep in mind that these alternatives may introduce additional complexity, trade-offs, or performance overhead.

Related benchmarks:

Array flat vs isArray check (version: 0)

Comparing performance of: Array.flat vs isArray check

Created: 4 years ago by: Guest

Jump to the latest result

Array.flat

isArray check

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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