Benchmark: Array vs SubArray splice

Script Preparation code:

var array = new Array();
const count = 100000; 
for(let i = 0; i < count; ++i)
	array.push(i);
	
class SubArray extends Array {
	constructor() {
		super();
	}
}
var subArray = new SubArray();
for(let i = 0; i < count; ++i)
	subArray.push(i);

Tests:

Array
array.splice(0, 1); array.push(123456789);
SubArray
subArray.splice(0, 1); subArray.push(123456789);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array
SubArray

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and explain what is being tested, compared, and the pros and cons of each approach.

**Benchmark Definition**

The benchmark definition consists of two main parts:

1. **Script Preparation Code**: This code creates an array with 100,000 elements using a `for` loop that pushes the current iteration counter `i` onto the array. It also defines a subclass `SubArray` extends `Array`. Another array is created and populated with 100,000 elements as well.
2. **Html Preparation Code**: This field is empty (`null`), indicating that no HTML code needs to be prepared for this benchmark.

**Individual Test Cases**

There are two individual test cases:

1. **Test Case 1: Array**
The script calls `array.splice(0, 1)`, removing the first element from the array, and then pushes a new value (123456789) onto the array.
2. **Test Case 2: SubArray**
The script calls `subArray.splice(0, 1)` on the `SubArray` instance, which removes the first element from its internal array, and then pushes a new value (123456789) onto that same internal array.

**What is being tested?**

These test cases are comparing the performance of:

* The native JavaScript `Array` class
* A custom subclass `SubArray` that extends `Array`

The main operation being tested is the usage of `splice()` on both arrays, which involves removing an element and then pushing a new value.

**Options compared**

The two options being compared are:

1. Using the native `Array` class (`array.splice(0, 1)` and `array.push(123456789)`)
2. Using the custom subclass `SubArray` (`subArray.splice(0, 1)` and `subArray.push(123456789)`)

**Pros and Cons of each approach**

* **Native Array**: Pros:
	+ Wide support across JavaScript engines
	+ Native performance
Cons:
	+ May not provide detailed insight into the underlying array implementation
* **Custom SubArray**: Pros:
	+ Can potentially reveal implementation details about the custom subclass
Cons:
	+ May have reduced support across JavaScript engines (or none at all)
	+ Performance may vary depending on the engine and implementation

**Library**

The `SubArray` class is a custom library or extension, likely used to compare the behavior of arrays under different circumstances. Its purpose is unclear without more context.

**Special JS feature or syntax**

There doesn't appear to be any special JavaScript features or syntax being tested in this benchmark.

**Other alternatives**

Other benchmarks might test:

* Using `splice()` on other types of arrays (e.g., `Set`, `Map`)
* Comparing performance with different array initializers (e.g., `Array.from()`, `Array.create()`)
* Testing the effect of other operations on array performance (e.g., `push()`, `pop()`, `shift()`, `unshift()`)

Keep in mind that these are just speculative examples, and the actual benchmark might test different aspects or variations.

Related benchmarks:

Array vs SubArray splice (version: 1)

Array vs SubArray splice

Comparing performance of: Array vs SubArray

Created: 4 years ago by: Registered User

Jump to the latest result

Array

SubArray

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):