Benchmark: Array.prototype.slice(0) vs spread operator

Script Preparation code:

var params = [ "hello", true, 7, "coucou", false, 6, "doudou", 5 ];

Tests:

Array.prototype.slice
var other = params.slice(0);
spread operator
var other = [ ...params ];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.slice
spread operator

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark and explain what's being tested, compared, and considered.

**Benchmark Definition**

The benchmark is testing two ways to create a shallow copy of an array: using the `Array.prototype.slice(0)` method and the new ES6 spread operator (`[ ...params ]`). The benchmark aims to compare the performance of these two approaches in JavaScript.

**Options Compared**

Two options are being compared:

1. **`Array.prototype.slice(0)`**: This is a traditional method for creating a shallow copy of an array. It returns a new array containing all elements from the original array, starting from the beginning (index 0) to the end.
2. **Spread Operator (`[ ...params ]`)**: This is a new ES6 feature that allows you to create a new array by spreading the elements of an existing array. The spread operator `...` distributes the elements of the `params` array into separate positions in the new array.

**Pros and Cons**

Here are some pros and cons of each approach:

* **`Array.prototype.slice(0)`**:
	+ Pros: widely supported, well-documented, and stable.
	+ Cons: can be slow for large arrays due to the overhead of creating a new array object.
* **Spread Operator (`[ ...params ]`)**:
	+ Pros: faster than `slice(0)` for large arrays, more concise, and flexible.
	+ Cons: not as widely supported (requires modern browsers), and might have performance issues in older environments.

**Library/Features Used**

None are explicitly mentioned in the provided benchmark definition. However, it's worth noting that some features like ES6 spread operator may require a modern JavaScript engine or browser to work correctly.

**Special JS Features/Syntax**

The spread operator (`[ ...params ]`) is a special feature introduced in ES6 (ECMAScript 2015). It allows for more concise and expressive array creation. The `slice(0)` method, on the other hand, is an older method that has been around since ECMAScript 1.

**Other Alternatives**

If you were to implement this benchmark yourself, some alternative approaches might include:

* Using `Array.prototype.concat()`: This method concatenates arrays and returns a new array. However, it's generally slower than the spread operator for large arrays.
* Using `Object.assign()`: This method copies properties from one or more source objects to a target object. You could use it to create an array copy, but it would be less efficient than using the spread operator.

Keep in mind that these alternatives might not be as relevant or performant as the spread operator for this specific benchmark.

I hope this explanation helps you understand what's being tested and compared in this JavaScript microbenchmark!

Latest run results:

Run details: (Test run date: 5 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/77.0.3865.120 Safari/537.36

Browser/OS: Chrome 77 on Windows

View result in a separate tab

Test name	Executions per second
Array.prototype.slice	9465605.0 Ops/sec
spread operator	8329038.5 Ops/sec

Related benchmarks:

Array.prototype.slice(0) vs spread operator (version: 0)

Compare the new ES6 spread operator with the traditional slice(0) method

Comparing performance of: Array.prototype.slice vs spread operator

Created: 5 years ago by: Guest

Jump to the latest result

Array.prototype.slice

spread operator

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):