Benchmark: Array.prototype.slice vs spread operator (better though)

Tests:

Array.prototype.slice
var other = [ "hello", true, 7 ].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

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

The provided JSON represents a benchmarking test case that compares two approaches for creating a shallow copy of an array in JavaScript: `Array.prototype.slice()` and the new ES6 spread operator (`...`).

**What is being tested?**

In this test, we're measuring which approach is faster and more efficient. The specific benchmark definition files are:

1. `var other = [ "hello", true, 7 ].slice();` - This code uses the traditional `Array.prototype.slice()` method to create a copy of the array.
2. `var params = [ "hello", true, 7 ]; var other = [ ...params ];` - This code uses the spread operator (`...`) to create a new array with the same elements as the original `params` array.

**Options compared**

We have two options being compared:

* **`Array.prototype.slice()`**: A traditional method for creating a shallow copy of an array.
* **Spread operator (`...`)**: A newer, more concise way of creating arrays in JavaScript (introduced in ECMAScript 2015).

**Pros and Cons**

Here are some pros and cons of each approach:

**`Array.prototype.slice()`**

Pros:

* Well-established and widely supported method.
* Easy to understand and use for most developers.

Cons:

* Can be slower than the spread operator, especially for large arrays.

**Spread operator (`...`)**

Pros:

* More concise and expressive syntax.
* Can be faster for large arrays due to its optimized implementation.

Cons:

* Introduced in ECMAScript 2015, which means older browsers may not support it.
* May require additional imports or polyfills for older browsers.

**Other considerations**

* **Library usage**: Neither of these approaches uses any external libraries. They are built-in JavaScript features.
* **Special JS feature/syntax**: The spread operator (`...`) is a new syntax introduced in ECMAScript 2015, which allows it to be used with arrays and other iterables.

**Alternative approaches**

Other alternatives for creating shallow copies of arrays include:

* `Array.prototype.concat()` - This method concatenates the elements of an array, but can be slower than both `slice()` and the spread operator.
* `Object.assign()` - This method creates a new object by copying elements from another object. While it can work for arrays, it's not as efficient as `slice()` or the spread operator.

In summary, the benchmark is testing which approach (traditional `Array.prototype.slice()`, or the new ES6 spread operator) is faster and more efficient when creating shallow copies of arrays in JavaScript.

Latest run results:

Run details: (Test run date: 4 months ago)

User agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Mobile Safari/537.36

Browser/OS: Chrome Mobile 124 on Android

View result in a separate tab

Test name	Executions per second
Array.prototype.slice	27539580.0 Ops/sec
spread operator	18695802.0 Ops/sec

Related benchmarks:

Array.prototype.slice vs spread operator (better though) (version: 0)

Compare the new ES6 spread operator with the traditional slice() method

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

Created: 4 months 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 26 days ago):