Benchmark: Array clone from index 1 to end: spread operator vs slice

Script Preparation code:

var arr = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

Tests:

spread operator
const arr1 = [ , ...arr ];
slice
const arr1 = arr.slice(1);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread operator
slice

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark is testing two approaches to create a clone of an array from index 1 to the end: using the spread operator (`...`) versus using the `slice()` method.

**Options Compared**

The two options being compared are:

1. **Spread Operator (`...`)**: This syntax creates a new array by spreading the elements of the original array, starting from the second element (index 1).
2. **Slice Method (`arr.slice(1)`)**: This method returns a shallow copy of a portion of an array, specifically the slice from index 1 to the end.

**Pros and Cons**

Here's a brief summary of the pros and cons of each approach:

* **Spread Operator (`...`)**:
	+ Pros:
		- More concise and readable code
		- Creates a new array without modifying the original
	+ Cons:
		- May be slower due to the overhead of creating a new array
		- Not all browsers support this syntax
* **Slice Method (`arr.slice(1)`)**:
	+ Pros:
		- Faster execution, as it's a built-in method that doesn't require creating a new array
		- Widely supported across most browsers and JavaScript engines
	+ Cons:
		- May be less readable due to the need for the `slice()` method

**Other Considerations**

The benchmark also considers other factors, such as:

* **Browser**: The test is run in Chrome 89 on a Windows Desktop.
* **Device Platform**: Desktop, indicating that mobile devices or other platforms are not tested.

**Library and Special JS Features**

In this benchmark, there is no library being used. However, it's worth noting that the spread operator was introduced in ECMAScript 2015 (ES6), so browsers may not support it if they're using an older JavaScript engine.

**Other Alternatives**

If you wanted to create a clone of an array from index 1 to the end, other alternatives could include:

* Using `Array.prototype.slice.call(arr, 1)` or `Array.prototype.slice.apply(arr, [1])` (older syntax for creating an array copy)
* Using `Array.from(arr, (_, i) => arr[i + 1])`, which is another spread-based approach
* Using a custom loop to create the clone

However, these alternatives may not be as concise or readable as the spread operator or slice method.

I hope this explanation helps you understand what's being tested in this benchmark!

Related benchmarks:

Array clone from index 1 to end: spread operator vs slice (version: 0)

Comparing performance of: spread operator vs slice

Created: 5 years ago by: Guest

Jump to the latest result

spread operator

slice

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):