Benchmark: test spread vs add in reduce

Tests:

spread
let divisions = [[1,2,3,4,5,6,7,8,9,10],[1,2,3,4],[1,2,3,4],[1,2,3,4]]; divisions.reduce((prev, cur) => [...prev, ...cur], []);
push
let divisions = [[1,2,3,4,5,6,7,8,9,10],[1,2,3,4],[1,2,3,4],[1,2,3,4]]; divisions.reduce((prev, cur) => (prev.push(...cur), prev), []);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread
push

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

The benchmark, named "test spread vs add in reduce", is designed to compare the performance of two approaches: using the spread operator (`...`) and using `push()` method with array elements. The benchmark creates an array of arrays, where each inner array contains a subset of numbers from the original array.

**Approach 1: Spread Operator**

The first approach uses the spread operator (`...`), which returns a new array by copying all elements from the source array and then spreading them out into an array. In this case, the code is:
```javascript
divisions.reduce((prev, cur) => [...prev, ...cur], []);
```
This code creates a new array by concatenating the elements of each inner array with the spread operator.

**Approach 2: push()**

The second approach uses the `push()` method to add elements to an existing array. In this case, the code is:
```javascript
divisions.reduce((prev, cur) => (prev.push(...cur), prev), []);
```
This code modifies the previous array by adding each element of the current inner array using `push()`.

**Pros and Cons**

Here are some pros and cons for each approach:

* **Spread Operator (`...`)**:
	+ Pros: creates a new array, which can be beneficial for performance and memory efficiency.
	+ Cons: may incur overhead due to creating a new array, especially for large datasets.
* **push()**:
	+ Pros: modifies the existing array in place, which can be more efficient than creating a new array.
	+ Cons: modifies the original array, which might not be desirable if you need to preserve the original data.

**Library and Special JS Features**

In this benchmark, no libraries are used, but it does use some standard JavaScript features:

* `reduce()`: a method that applies a function to each element of an array and reduces it to a single value.
* Spread operator (`...`): a syntax feature introduced in ECMAScript 2015 (ES6).
* `push()` method: a built-in array method.

**Other Alternatives**

If you're looking for alternative approaches, here are some options:

* Using `concat()` instead of spread operator: `divisions.reduce((prev, cur) => prev.concat(cur), [])`
* Using `array.prototype.push.apply()` or `Array.prototype.pushAll()` instead of push(): `divisions.reduce((prev, cur) => Array.prototype.push.apply(prev, cur), [])`

Keep in mind that the performance difference between these approaches may be negligible for small datasets, but it can become significant for larger datasets.

Related benchmarks:

test spread vs add in reduce (version: 0)

1234567890

Comparing performance of: spread vs push

Created: 4 years ago by: Guest

Jump to the latest result

spread

push

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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