Benchmark: Array.prototype.slice vs spread operator by sean

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/120.0.0.0 Safari/537.36

Browser/OS: Chrome 120 on Windows

View result in a separate tab

Test name	Executions per second
Array.prototype.slice	233681264.0 Ops/sec
spread operator	133204992.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

The provided JSON represents two test cases for measuring the performance difference between the traditional `Array.prototype.slice()` method and the new ES6 spread operator (`...`).

**What is tested:**

Two options are compared:

1. **Traditional `Array.prototype.slice()`:**
	* This method creates a shallow copy of an array by returning a new array object with references to the same elements as the original array.
2. **New ES6 spread operator (`...`):**
	* This operator creates a new array by spreading the elements of the original array into a new array.

**Pros and Cons:**

1. Traditional `Array.prototype.slice()`: 
	* Pros:
		+ Widely supported across browsers and Node.js versions.
		+ Easy to understand and implement.
	* Cons:
		+ Creates a new array object, which can lead to increased memory usage.
		+ Can be slower due to the overhead of creating a new array object.
2. New ES6 spread operator (`...`):
	* Pros:
		+ Creates a new array with minimal overhead (only a reference to the original elements).
		+ Supports shallow copying of arrays.
	* Cons:
		+ Not yet widely supported across older browsers and Node.js versions.
		+ Can lead to issues when dealing with complex data structures or objects.

**Library:**

There is no specific library mentioned in the provided JSON. However, the use of ES6 syntax (`...`) indicates that the benchmark assumes a modern JavaScript environment that supports this feature.

**Special JS feature or syntax:**

The benchmark uses the new ES6 spread operator (`...`), which was introduced in ECMAScript 2015 (ES6). This feature allows for concise array creation and is widely supported across modern browsers and Node.js versions.

**Benchmark preparation code:**

The provided JSON doesn't contain any script preparation code, which means that the benchmarking environment will likely use a simple test case where an array is created with some elements, and then either `slice()` or the spread operator is used to create a new copy of the array. The exact implementation details are not shown in this JSON.

**Other alternatives:**

If the traditional `Array.prototype.slice()` method were not available, other alternatives for creating a shallow copy of an array might include:

* Using the `Array.from()` method with the `Map` constructor (e.g., `Array.from([1, 2, 3], () => new Map([[0, 1], [1, 2]])`). Note that this approach can be slower due to the overhead of creating a new map object.
* Using a library like Lodash's `cloneDeep()` function or another third-party utility for array cloning.

Keep in mind that these alternatives might have different performance characteristics and may not be suitable for all use cases.

Related benchmarks:

Array.prototype.slice vs spread operator by sean (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>

Fastest: N/A

Slowest: N/A

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