Benchmark: Reverse vs ToReversed

Script Preparation code:

var arr = new Array(100000000).fill(0);

Tests:

Reverse
Array.from(arr).reverse()
toReversed
arr.toReversed()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Reverse
toReversed

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36 OPR/112.0.0.0

Browser/OS: Opera 112 on Windows

View result in a separate tab

Test name	Executions per second
Reverse	2.0 Ops/sec
toReversed	2.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the explanation of this JavaScript microbenchmark.

**Benchmark Definition JSON**

The benchmark is defined by a JSON object with the following properties:

* `Name`: The name of the benchmark, which in this case is "Reverse vs ToReversed".
* `Description`: An empty string, indicating that there is no description for this benchmark.
* `Script Preparation Code` and `Html Preparation Code`: These two properties are used to set up the environment for the benchmark. In this case, they create an array of 100 million zeros (`var arr = new Array(100000000).fill(0);`) and do not specify any HTML code.

**Individual Test Cases**

The benchmark consists of two test cases:

1. `Reverse`: The first test case uses the `Array.prototype.reverse()` method to reverse the order of elements in the `arr` array.
2. `toReversed`: The second test case uses a custom function called `toReversed()` (not shown in this JSON snippet) to reverse the order of elements in the `arr` array.

**Library and Purpose**

The `toReversed()` function is not part of the standard JavaScript library, but it's likely a custom implementation provided by the benchmark creator. The purpose of this function is unclear without more information, but it might be designed to test the performance of different array reversal algorithms or implementations.

**Options Compared**

In this benchmark, two options are being compared:

* **Native `Array.prototype.reverse()`**: This is the built-in method for reversing arrays in JavaScript. It uses a complex algorithm that involves swapping elements and shifting indices.
* **Custom `toReversed()` function**: As mentioned earlier, this is a custom implementation of array reversal provided by the benchmark creator.

**Pros and Cons**

Here are some pros and cons of each approach:

1. Native `Array.prototype.reverse()`:
	* Pros: Widely supported, efficient, and well-optimized.
	* Cons: Can be slower for very large arrays due to its algorithmic complexity.
2. Custom `toReversed()` function:
	* Pros: Allows for customization and potential optimization of the reversal algorithm.
	* Cons: May not be as widely supported or optimized as the native method.

**Other Considerations**

When running this benchmark, several other factors can affect performance:

* **Array size**: Larger arrays like 100 million elements can lead to increased memory usage and slower performance.
* **Browser support**: The performance of `Array.prototype.reverse()` may vary between browsers due to differences in engine optimizations.
* **JavaScript engine optimizations**: Some JavaScript engines might optimize the native method or custom implementation differently, affecting performance.

**Alternatives**

If you wanted to write a similar benchmark, you could consider using other array reversal methods, such as:

* Using `Array.prototype.map()` and `Array.prototype.reverse()`
* Implementing a custom algorithm using loops and indices
* Utilizing libraries like Lodash or Ramda for array manipulation

Keep in mind that the choice of implementation will depend on your specific use case, target audience, and performance requirements.

Related benchmarks:

Reverse vs ToReversed (version: 0)

Comparing performance of: Reverse vs toReversed

Created: 3 months ago by: Guest

Jump to the latest result

Reverse

toReversed

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):