Benchmark: Compare Concat->Push with Spread->Concat

Tests:

Concat and Push
var init = [10,11,12,13]; var params = [ [1, 2], [3,4 ], [5, 6], [7, 8 ]]; init.push(...([]).concat(...params)); console.log(init);
Spread And Concat
var init = [10,11,12,13]; var params = [ [1, 2], [3,4 ], [5, 6], [7, 8 ]]; init = init.concat(...params); console.log(init);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Concat and Push
Spread And Concat

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.164 Safari/537.36

Browser/OS: Chrome 91 on Windows

View result in a separate tab

Test name	Executions per second
Concat and Push	10246.2 Ops/sec
Spread And Concat	14283.5 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 its test cases.

**What is being tested?**

The benchmark compares two approaches to merge arrays in JavaScript:

1. **Concat->Push**: This approach involves using the `concat()` method to merge an array with another array, followed by using the spread operator (`...`) to push elements from a third array into the resulting array.
2. **Spread->Concat**: This approach involves using the spread operator (`...`) to merge two arrays, and then using the `concat()` method to concatenate the result with another array.

**Options compared**

The benchmark compares these two approaches:

* **Approach 1: Concat->Push**
	+ Uses `concat()` to merge an array with another array
	+ Uses `push()` to add elements from a third array to the resulting array
* **Approach 2: Spread->Concat**
	+ Uses spread operator (`...`) to merge two arrays
	+ Uses `concat()` to concatenate the result with another array

**Pros and Cons of each approach**

**Concat->Push (Approach 1)**

Pros:

* Typically faster than spread operators, since `push()` is a low-cost operation compared to `concat()`
* Can be more memory-efficient, since it avoids creating intermediate arrays
* Well-supported by most browsers and JavaScript engines

Cons:

* Can lead to performance issues if the input arrays are large or complex
* May have higher memory overhead due to the creation of temporary arrays

**Spread->Concat (Approach 2)**

Pros:

* Generally faster than `concat()` for merging small to medium-sized arrays
* More concise and expressive code
* Easier to read and maintain, as it avoids the need for explicit array manipulation

Cons:

* Can be slower than `push()` for very large or complex arrays due to the overhead of creating intermediate arrays
* Less supported by older browsers and JavaScript engines

**Library usage**

There is no library used in this benchmark.

**Special JS features or syntax**

The benchmark uses the following special feature/syntax:

* Spread operator (`...`)

The spread operator was introduced in ECMAScript 2015 (ES6) as a way to expand an array into individual elements, allowing for more concise and expressive code. It is widely supported by modern browsers and JavaScript engines.

**Alternative approaches**

Other alternatives for merging arrays include:

* Using `Array.prototype.reduce()` or `Array.prototype.flatMap()`
* Using libraries like Lodash or Ramda
* Using other array methods like `Array.prototype.slice()` or `Array.prototype.splice()`

However, these alternatives may not be as efficient or concise as the spread operator and `concat()` combination used in this benchmark.

Related benchmarks:

Compare Concat->Push with Spread->Concat (version: 2)

Compare Concat->Push with Spread->Concat

Comparing performance of: Concat and Push vs Spread And Concat

Created: 3 years ago by: Registered User

Jump to the latest result

Concat and Push

Spread And Concat

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):