Benchmark: [].concat() vs flat()

Tests:

reduce + Array.prototype.concat
var params = [[ 1, 2 ], [ "hello", true, 7 ]]; var other = [].concat(...params);
Array.prototype.flat
var params = [[1, 2, params], [ "hello", true, 7 ]]; var other = params.flat();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

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

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:130.0) Gecko/20100101 Firefox/130.0

Browser/OS: Firefox 130 on Linux

View result in a separate tab

Test name	Executions per second
reduce + Array.prototype.concat	15357805.0 Ops/sec
Array.prototype.flat	16091137.0 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 JSON and explain what's being tested.

**Benchmark Definition**

The benchmark is comparing two approaches:

1. `[] .concat()` (traditional method)
2. `...` spread operator (`flat()`)

**Pros and Cons of Different Approaches**

* Traditional `.concat()`:
	+ Pros: well-established, widely supported, easy to understand.
	+ Cons: can lead to shallow copying, resulting in performance issues when dealing with large arrays.
* Spread operator (`...`) with `flat()`:
	+ Pros: provides a more concise and expressive way of concatenating arrays, handles nested arrays automatically.
	+ Cons: requires modern JavaScript versions (ES6+) and may not work in older browsers.

**Library and Special JS Features**

In the individual test cases:

* The first test case uses the `reduce()` method, which is a built-in JavaScript method that applies a function to each element of an array and reduces it to a single value. This feature was introduced in ECMAScript 2015 (ES6).
* The second test case uses the spread operator (`...`) with the `flat()` method, which is also a part of the modern JavaScript standard library.

**Other Considerations**

When comparing these two approaches, we should consider factors like:

* Performance: How do these methods compare in terms of execution speed?
* Code readability and maintainability: Which approach makes the code more concise and easier to understand?
* Browser support: Are both methods supported by older browsers?

**Alternatives**

If you're interested in exploring alternative approaches, here are a few options:

1. Using `Array.prototype.push()` instead of `.concat()`: This method is also widely supported but may not be as concise.
2. Using `Array.prototype spread` (newest browsers only): In newer browsers that support the spread operator, you can use it to concatenate arrays in a more concise way.

For example:
```javascript
var arr1 = [1, 2];
var arr2 = [...arr1, ...[3, 4]];
```
Keep in mind that browser support for these alternatives may be limited.

In summary, the benchmark is comparing two approaches for array concatenation: traditional `.concat()` and the modern spread operator (`flat()`). The pros of the spread operator include conciseness and automatic handling of nested arrays. However, it requires modern JavaScript versions and may not work in older browsers.

Related benchmarks:

[].concat() vs flat() (version: 0)

Compare the new ES6 spread operator with the traditional concat() method

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

Created: 4 years ago by: Guest

Jump to the latest result

reduce + 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):