Benchmark: Array.prototype.slice vs spread operator for copying

Tests:

Array.prototype.slice
const params = [ "hello", true, 7 ]; const other = params.slice();
spread operator
const params = [ "hello", true, 7 ] const 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

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 provided benchmark and explain what's being tested, compared, and their pros and cons.

**Benchmark Overview**

The test compares two ways to copy an array in JavaScript:

1. Using `Array.prototype.slice()`
2. Using the spread operator (`...`)

**What is being tested?**

In this case, the test is measuring the performance difference between these two methods of creating a shallow copy of an array.

**Options compared:**

* `Array.prototype.slice()` vs. Spread Operator (`...`)

**Pros and Cons of each approach:**

* **Array.prototype.slice():**
	+ Pros:
		- Wide browser support (since it's part of the standard library)
		- Simple and intuitive syntax
	+ Cons:
		- Can be slower than the spread operator for large arrays, since it requires creating a new array object with a reference to the original array
* **Spread Operator (`...`):**
	+ Pros:
		- Fast and efficient, especially for large arrays
		- Newer syntax that's gaining widespread adoption
	+ Cons:
		- May not work in older browsers or environments (since it's not part of the standard library yet)
		- Requires understanding of the spread operator syntax

**Library/Dependency:**

None explicitly mentioned, but the spread operator relies on the `Object.values()` and `Object.assign()` methods, which are built-in functions in modern JavaScript.

**Special JS Feature/Syntax:**

The spread operator (`...`) is a relatively new feature introduced in ECMAScript 2018 (ES2018). It allows creating a new array from an iterable source by spreading its elements into an array. This syntax is widely supported in modern browsers and engines, but may not work in older environments.

**Other alternatives:**

There are other ways to create a shallow copy of an array, such as:

* `Array.prototype.slice.call()`
* `Array.prototype.slice.apply()`
* `Array.prototype.map()` (which creates a new array with the same elements)
* Using `JSON.parse(JSON.stringify(obj))` for primitive types

However, these alternatives are generally less efficient or more cumbersome than using `slice()` or the spread operator.

Overall, this benchmark provides a simple and straightforward comparison between two commonly used methods of creating a shallow copy of an array in JavaScript.

Related benchmarks:

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

Compare ES6 spread operator with the traditional slice() method

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

Created: 2 years ago by: Guest

Jump to the latest result

Array.prototype.slice

spread operator

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):