Benchmark: flatten arrays 11241243

Script Preparation code:

var entries = 1000;
var a = [];
var b = [];
var c = [];
var d = [];
var e = [];
var f = [];
for (var i = 0; i < entries; i++) {
  a[i] = Math.random();
  b[i] = Math.random();
  c[i] = Math.random();
  d[i] = Math.random();
  e[i] = Math.random();
  f[i] = Math.random();
}
 var arrayOfArrays = [a, b, c, d, e, f];

Tests:

Array.flat()
var result1 = arrayOfArrays.flat();
Reduce
var result2 = arrayOfArrays.reduce((a, subArray) => a.concat(subArray), []);
forEach
var result3 = []; arrayOfArrays.forEach((subArray) => Array.prototype.push.apply(result3, subArray));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.flat()
Reduce
forEach

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

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

**Benchmark Definition JSON**

The benchmark definition is a script that creates two arrays (`a` and `b`) with 1000 random numbers each, then combines them into an array of arrays (`arrayOfArrays`). This script serves as the input for the various test cases.

**Options Compared**

Three options are being compared:

1. **Array.flat()**: A method introduced in ECMAScript 2019 (ES10) that flattens an array of arrays into a single array.
2. **Reduce**: An Array.prototype method that reduces an array to a single value by applying a callback function to each element.
3. **forEach**: A method introduced in ECMAScript 2009 (ES5) that executes a provided function once for each element in an array.

**Pros and Cons of Each Approach**

1. **Array.flat()**:
	* Pros: Efficient, concise, and expressive. It's also relatively new, which might make it more likely to be implemented efficiently by browsers.
	* Cons: Not supported in older browsers (pre-ES10), so it may not be a viable option for testing older JavaScript engines.
2. **Reduce**:
	* Pros: Widely supported, even in very old browsers (pre-ES5). It's also a built-in method, making it easy to implement.
	* Cons: Can be less readable and more verbose than other methods, especially for complex data transformations.
3. **forEach**:
	* Pros: Simple and widely supported. It's also relatively fast, as it avoids creating intermediate arrays.
	* Cons: May not be the most efficient option, as it requires an explicit loop and may create unnecessary memory allocations.

**Library and Purpose**

In this benchmark, no external library is being used. However, if a library like Lodash were used, `_.flatten()` or `_.map()` could potentially replace some of these methods.

**Special JS Feature or Syntax (None)**

There are no special JavaScript features or syntaxes being tested in this benchmark.

**Other Alternatives**

In addition to the three options being compared, other approaches might include:

* Using a library like Lodash for flattening arrays
* Using `Array.prototype.map()` to create a new array with flattened values
* Using a custom loop and indexing to flatten the array

Keep in mind that these alternatives may not be as efficient or readable as the methods being compared.

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.88 Safari/537.36

Browser/OS: Chrome 79 on Windows

View result in a separate tab

Test name	Executions per second
Array.flat()	784.2 Ops/sec
Reduce	39239.0 Ops/sec
forEach	17066.3 Ops/sec

Related benchmarks:

flatten arrays 11241243 (version: 0)

Comparing performance of: Array.flat() vs Reduce vs forEach

Created: 5 years ago by: Guest

Jump to the latest result

Array.flat()

Reduce

forEach

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):