Benchmark: Slice vs Spread - MeasureThat.net

Tests:

Slice
let array = [1, 2, 3, 4, 5]; let newArray = array.slice();
Spread
let array = [1, 2, 3, 4, 5]; let newArray = [...array];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Slice
Spread

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):

LLMs can make mistakes. Check important info.

I'll break down the explanation into smaller parts to make it easier to understand.

**What is being tested?**

The provided JSON represents two individual test cases: "Slice" and "Spread". These test cases compare the performance of two different methods for creating a new array from an existing one:

1. `array.slice()`: This method creates a shallow copy of the original array, returning a new array object with references to the same elements as the original array.
2. `[...array]`: This is called the spread operator or "spread syntax". It creates a new array by copying all elements from the original array.

**Options compared**

The two options being compared are:

1. **Slicing**: Using `slice()` method to create a new array.
	* Pros:
		+ Creates a shallow copy of the original array, which can be efficient for large arrays.
		+ Can be faster than spread operator for very large arrays (since it doesn't involve creating multiple copies).
	* Cons:
		+ Only creates a shallow copy, leaving references to the same elements as the original array.
		+ May not be suitable for all use cases where you need to create a completely independent copy of the array.
2. **Spread operator**: Using the spread operator (`[...array]`) to create a new array.
	* Pros:
		+ Creates a deep copy of the original array, which can be more efficient than slicing (especially for large arrays) since it involves creating multiple copies.
		+ Suitable for all use cases where you need to create a completely independent copy of the array.
	* Cons:
		+ May be slower than slicing for very large arrays due to the overhead of creating multiple copies.

**Library and special JS features**

There are no libraries mentioned in this benchmark, but I'll note that JavaScript 2015 introduced the spread operator (`[...array]`) as a way to create new arrays from existing ones. This feature was later adopted by most modern browsers.

No special JavaScript features or syntax are mentioned in this benchmark.

**Other alternatives**

In addition to slicing and the spread operator, there are other ways to create a new array in JavaScript:

1. `Array.prototype.slice.call(array)`: This creates a new array from an existing one, but it's less efficient than using the spread operator.
2. `Array.from()` method: This creates a new array from an existing iterable (such as an array or string). While not exactly equivalent to slicing or the spread operator, it can be used in similar contexts.

Keep in mind that these alternatives might have different performance characteristics and use cases compared to slicing and the spread operator.

I hope this explanation helps!

Latest run results:

Run details: (Test run date: 6 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36

Browser/OS: Chrome 67 on Mac OS X 10.13.3

View result in a separate tab

Test name	Executions per second
Slice	66557148.0 Ops/sec
Spread	18510816.0 Ops/sec

Related benchmarks:

Slice vs Spread (version: 0)

Slice vs Spread

Comparing performance of: Slice vs Spread

Created: 6 years ago by: Guest

Jump to the latest result

Slice

Spread

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):