Benchmark: concat() vs flat()

Script Preparation code:

var params = [[ 1, 2 ], [ "hello", true, 7 ], [ "fear", "not" ]];

Tests:

Array.prototype.concat
var other = params[0].concat(params[1], params[2]);
Array.prototype.flat
var other = params.flat();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.concat
Array.prototype.flat

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/116.0.0.0 Safari/537.36

Browser/OS: Chrome 116 on Windows

View result in a separate tab

Test name	Executions per second
Array.prototype.concat	2533182.8 Ops/sec
Array.prototype.flat	630972.4 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark definition and test cases to understand what's being tested.

**What is being tested:**

The benchmark compares the performance of two methods in JavaScript: `concat()` and `flat()`. These methods are part of the Array prototype, which means they're used on arrays (ordered collections of values).

**Options compared:**

1. **Array.prototype.concat()**: This method returns a new array that is a shallow copy of one or more arrays. It takes an arbitrary number of arguments.
2. **Array.prototype.flat()**: This method flattens an array (which can be deeply nested) into a one-dimensional array.

**Pros and Cons:**

* **concat():**
	+ Pros:
		- Simple to understand and implement.
		- Works well for concatenating arrays with similar types of elements.
	+ Cons:
		- Can create new objects if the input arrays contain objects, which can be memory-intensive.
		- Not suitable for flattening deeply nested arrays.
* **flat():**
	+ Pros:
		- More efficient than concat() when dealing with large arrays or deep nesting.
		- Reduces memory allocation by creating a single-level array.
	+ Cons:
		- Can be slower due to its recursive nature (it uses heappop and push operations).
		- Not as intuitive for non-developers.

**Library usage:**

None mentioned in the benchmark definition. Both `concat()` and `flat()` are built-in JavaScript methods, so no external libraries are required.

**Special JS feature or syntax:**

* **Spread syntax (`...`)** is not used in this benchmark.
* However, it's worth noting that `flat()` was introduced in ECMAScript 2019 (ES10), which may affect its behavior and performance in older browsers or environments that don't support the latest standards.

**Other alternatives:**

If you need to flatten arrays or concatenate them, other methods can be used:

* For concatenation:
	+ Use `Array.prototype.push()` to append elements from one array to another.
	+ Use a library like Lodash (`_.concat()`) if you prefer a more concise solution.
* For flattening arrays:
	+ Use `Array.prototype.reduce()` with a callback function to recursively flatten the array.
	+ Use a library like Lodash (`_.flatten()`) for a more efficient and concise implementation.

Keep in mind that these alternatives may have different performance characteristics and use cases compared to `concat()` and `flat()`.

Related benchmarks:

concat() vs flat() (version: 0)

Compare concat() and flat() methods

Comparing performance of: Array.prototype.concat vs Array.prototype.flat

Created: one year ago by: Guest

Jump to the latest result

Array.prototype.concat

Array.prototype.flat

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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