Benchmark: JS array spread operator vs push

Tests:

Push
var params = [ 1, 2 ]; params.push(1);
Spread operator
var params = [ 1, 2 ] params = [ ...params, 1 ]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Push
Spread operator

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/117.0

Browser/OS: Firefox 117 on Ubuntu

View result in a separate tab

Test name	Executions per second
Push	32070830.0 Ops/sec
Spread operator	16739762.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Purpose**

The benchmark aims to compare the insertion efficiency of two approaches:

1. **Push**: Using the `push` method to add an element to the end of an array.
2. **Spread Operator**: Using the spread operator (`...`) to create a new array with the original elements and the newly added element.

**Options Compared**

The benchmark compares these two options because they have different performance characteristics:

* The `push` method involves updating the length property of the array, which can lead to slower performance.
* The spread operator creates a new array object by copying the existing elements, which can be more efficient for larger arrays.

**Pros and Cons of Each Approach**

1. **Push**
	* Pros: Simple, widely supported, and works well for small arrays.
	* Cons: Can lead to slower performance due to updating the length property, especially for large arrays.
2. **Spread Operator**
	* Pros: More efficient for larger arrays since it creates a new array object without updating the length property.
	* Cons: Requires modern JavaScript features (introduced in ECMAScript 2018) and may not work in older browsers.

**Library/Tool Used**

There is no specific library or tool mentioned in the benchmark definition. However, the benchmark uses the `...` spread operator, which is a built-in feature of JavaScript introduced in ECMAScript 2015 (ES6).

**Special JS Feature/Syntax**

The benchmark uses a modern JavaScript feature: the spread operator (`...`). This feature was introduced in ECMAScript 2015 (ES6) and allows creating new arrays by copying existing elements. While not all browsers support this feature, it's widely supported in modern browsers.

**Alternative Approaches**

Other alternatives for inserting an element into an array could include:

* Using the `unshift` method instead of `push`.
* Creating a new array using the `Array.from()` method and adding the element to it.
* Using a library like Lodash, which provides a `compact` function that can be used to add elements to an array.

However, these alternatives may not be as efficient or widely supported as the push method or the spread operator.

Related benchmarks:

JS array spread operator vs push (version: 0)

test insertion efficiency

Comparing performance of: Push vs Spread operator

Created: 2 years ago by: Guest

Jump to the latest result

Push

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):