Benchmark: slice vs new allocation3

Script Preparation code:

var arr = [];
for (let i = 0; i < 1000000; i++) {
  arr.push(i);
}

Tests:

Slice
for (let i = 0; i < 1000; i++) { arr.slice(i * 10, 1000) }
slice and save
const arr = []; for (let i = 0; i < 1000; i++) { arr.push(arr.slice(i * 10, 1000)) }
slice and renew
const arr = []; for (let i = 0; i < 1000; i++) { arr.push(Array.from(arr.slice(i * 10, 1000))) }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Slice
slice and save
slice and renew

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.0.0 Safari/537.36

Browser/OS: Chrome 109 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Slice	12171.9 Ops/sec
slice and save	56759.6 Ops/sec
slice and renew	7604.3 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 JSON data to understand what is being tested in this JavaScript microbenchmark.

**Benchmark Definition**
The benchmark definition describes a set of tests designed to compare three different approaches for slicing an array:

1. **Original Approach**: `arr.slice(i * 10, 1000)`
2. **Save and Create New Array**: `arr.push(arr.slice(i * 10, 1000))`
3. **Create a New Array and Slice**: `Array.from(arr.slice(i * 10, 1000))`

**Options Compared**
The three approaches differ in how they handle the slicing of the array:

* **Original Approach**: Slices the original array `arr` directly.
* **Save and Create New Array**: Creates a new array by pushing a slice of `arr` into itself. This approach creates multiple temporary arrays during execution.
* **Create a New Array and Slice**: Uses the `Array.from()` method to create a new array from the sliced portion of `arr`. This approach also creates a new array, but it does so more efficiently than the "Save and Create New Array" approach.

**Pros and Cons**

* **Original Approach**:
	+ Pros: Minimal overhead in creating temporary arrays.
	+ Cons: May not be as efficient due to direct slicing of the original array.
* **Save and Create New Array**:
	+ Pros: Can be faster than the "Original Approach" due to caching effects.
	+ Cons: Creates multiple temporary arrays during execution, leading to increased memory allocation and deallocation overhead.
* **Create a New Array and Slice**:
	+ Pros: More efficient than the "Save and Create New Array" approach by avoiding unnecessary array allocations.
	+ Cons: Requires using the `Array.from()` method, which may incur additional overhead for some browsers.

**Library Usage**
There is no explicit library usage in this benchmark. However, it's worth noting that some browsers might have internal optimizations or caching mechanisms that affect the performance of these approaches.

**Special JS Features or Syntax**
This benchmark does not explicitly use any special JavaScript features or syntax. The test cases are straightforward and utilize standard array methods like `slice()` and `push()`, as well as the `Array.from()` method.

**Other Alternatives**
If you were to modify this benchmark, alternative approaches could include:

* Using `splice()` instead of `slice()`
* Utilizing `map()` or `reduce()` for array slicing
* Implementing custom array allocation and deallocation algorithms
* Comparing different caching strategies or optimizations

Keep in mind that any modifications would require significant changes to the benchmark definition and test cases.

Related benchmarks:

slice vs new allocation3 (version: 0)

Comparing performance of: Slice vs slice and save vs slice and renew

Created: one year ago by: Guest

Jump to the latest result

Slice

slice and save

slice and renew

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):