Benchmark: Array.prototype.slice vs spread operator - fixed

Tests:

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

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/106.0.0.0 Safari/537.36

Browser/OS: Chrome 106 on Windows

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Test name	Executions per second
Array.prototype.slice	102963976.0 Ops/sec
spread operator	54043520.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'd be happy to explain the benchmark and its results.

**Benchmark Purpose**

The MeasureThat.net benchmark compares the performance of two approaches for creating a copy of an array in JavaScript: the traditional `Array.prototype.slice()` method and the new ES6 spread operator (`[...array]`). The benchmark aims to determine which approach is faster and more efficient.

**Options Compared**

Two options are compared:

1. **`Array.prototype.slice()`**: This is a built-in method for creating a shallow copy of an array.
2. **Spread Operator (`[...]`)**: This is a new syntax introduced in ES6 that allows creating a new array by spreading the elements of an existing array.

**Pros and Cons**

Here are some pros and cons of each approach:

* `Array.prototype.slice()`
	+ Pros:
		- Widely supported across different browsers and versions.
		- Can be used with any type of data, not just arrays.
	+ Cons:
		- Creates a shallow copy, which can lead to unexpected behavior if the original array contains mutable objects.
		- Can be slower than the spread operator for large arrays.
* Spread Operator (`[...]`)
	+ Pros:
		- Faster than `Array.prototype.slice()` for large arrays (since it only creates a new array reference, without actually copying data).
		- Creates a shallow copy, which is sufficient for most cases.
	+ Cons:
		- Not supported in older browsers or versions of Internet Explorer.
		- Can be less intuitive to use than `Array.prototype.slice()`.

**Library and Special JS Features**

There are no external libraries used in this benchmark. However, the spread operator was introduced as a new syntax in ES6, which is a standard for modern JavaScript development.

**Test Case Explanation**

The test cases demonstrate how each approach creates a copy of an array:

1. `Array.prototype.slice()`: The code uses `params.slice()` to create a shallow copy of the `params` array.
2. Spread Operator (`[...]`): The code uses `[...params]` to create a new array by spreading the elements of the `params` array.

**Other Alternatives**

For creating an array copy, other alternatives include:

* Using `Array.from()` method: This creates a shallow copy of an array-like object.
* Using the `map()` method with a callback function: This can be used to create a new array by applying a transformation function to each element in the original array.

However, these alternatives may have different performance characteristics or requirements compared to `Array.prototype.slice()` and the spread operator.

Related benchmarks:

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

Compare the new 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>

Experimental features:

Fastest: N/A

Slowest: N/A

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