Benchmark: Splice vs deconstruction based copy

Script Preparation code:

var array = Array(100).fill(1);

Tests:

splice
let i = 10000; while(i>0) { const t1 = array.splice() i--; }
deconstruct
let i = 10000; while(i>0) { const t1 = [...array]; i--; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
splice
deconstruct

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/102.0.5005.63 Safari/537.36

Browser/OS: Chrome 102 on Windows

View result in a separate tab

Test name	Executions per second
splice	636.7 Ops/sec
deconstruct	377.5 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the benchmark and explain what's being tested, compared options, pros and cons, library usage, special JS features or syntax, and other considerations.

**Benchmark Definition**

The benchmark is titled "Splice vs deconstruction based copy". It tests two approaches to creating a shallow copy of an array: using `Array.prototype.splice()` and using the spread operator (`...`).

**Script Preparation Code**
```javascript
var array = Array(100).fill(1);
```
This code creates an array with 100 elements, all initialized to 1.

**Html Preparation Code**

There is no HTML preparation code provided, which suggests that this benchmark only tests JavaScript performance and does not consider DOM-related overhead.

**Individual Test Cases**

The benchmark consists of two test cases:

### Splice

```javascript
let i = 10000;
while(i>0) {
  const t1 = array.splice();
  i--;
}
```
This code uses `Array.prototype.splice()` to remove elements from the original array. The variable `t1` will be assigned the removed element, but it's not clear what value this variable holds (it might be `undefined`, depending on how many elements are removed).

### Deconstruction

```javascript
let i = 10000;
while(i>0) {
  const t1 = [...array];
  i--;
}
```
This code uses the spread operator (`...`) to create a shallow copy of the original array. The variable `t1` is assigned a reference to the copied array.

**Comparison**

The benchmark tests which approach (splice vs deconstruction) results in faster execution.

**Options Compared**

* Using `Array.prototype.splice()` to remove elements from an array.
* Using the spread operator (`...`) to create a shallow copy of an array.

**Pros and Cons**

* **Splice:**
	+ Pros:
		- Simple and well-known syntax.
	+ Cons:
		- Can be slower due to the overhead of removing elements from an array.
		- May not preserve the original array's structure or properties.
* **Deconstruction:**
	+ Pros:
		- Faster execution compared to splice.
		- Preserves the original array's structure and properties.
	+ Cons:
		- Less well-known syntax, which might be unfamiliar to some developers.

**Library Usage**

There is no library usage in this benchmark. Both `Array.prototype.splice()` and the spread operator are built-in JavaScript features.

**Special JS Feature or Syntax**

None mentioned explicitly, but it's worth noting that the spread operator (`...`) was introduced in ECMAScript 2015 (ES6). If you're using an older version of JavaScript, this benchmark might not be relevant to your use case.

**Other Considerations**

The benchmark only tests JavaScript performance and does not consider other factors like memory usage or garbage collection. Additionally, the test cases do not account for edge cases, such as empty arrays or arrays with a single element.

**Alternatives**

If you're interested in comparing other array manipulation approaches, you could explore:

* Using `Array.prototype.slice()`
* Using `Array.prototype.map()` and `Array.prototype.forEach()`
* Using `Buffer` APIs (e.g., `Buffer.from()`, `Buffer.concat()`)
* Using external libraries or frameworks for array manipulation (e.g., Lodash, Ramda)

Related benchmarks:

Splice vs deconstruction based copy (version: 0)

Comparing performance of: splice vs deconstruct

Created: 4 years ago by: Guest

Jump to the latest result

splice

deconstruct

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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