Benchmark: test1 array concat vs spred 2000+1000

Script Preparation code:

var arr1 = new Array(2000).fill(124);
var arr2 = new Array(2000).fill(541);

Tests:

spred
var other = [ ...arr1, ...arr2 ]
concat
var other = arr1.concat(arr2);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spred
concat

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.146 Safari/537.36

Browser/OS: Chrome 88 on Linux

View result in a separate tab

Test name	Executions per second
spred	53266.9 Ops/sec
concat	284664.9 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 help explain the provided benchmark.

**Benchmark Purpose and Options**

The provided benchmark is designed to compare two different approaches for concatenating two arrays in JavaScript: using `Array.prototype.concat()` (denoted as "concat") and using the spread operator (`...`) (denoted as "spred").

**Options Compared**

1. **`Array.prototype.concat()`**: This method creates a new array by copying elements from both input arrays.
2. **Spread Operator (`...`)**: This operator creates a new array by spreading the elements of one or more arrays.

**Pros and Cons**

* **Concatenation (concat)**:
	+ Pros: widely supported, easy to read and understand, can handle large datasets efficiently.
	+ Cons: creates a new array object, which can lead to memory overhead for very large datasets.
* **Spread Operator (`...`)**:
	+ Pros: creates a new array with minimal memory overhead, can be more efficient than concatenation for large datasets.
	+ Cons: syntax may not be as intuitive for some developers, requires JavaScript version 8 or later.

**Library and Special JS Feature**

None of the provided benchmarks use any external libraries. The spread operator is a built-in feature in modern JavaScript (since ECMAScript 2015).

No special JavaScript features are mentioned in this benchmark, but it's worth noting that the use of `Array.prototype.concat()` and the spread operator might not be supported by older versions of JavaScript.

**Alternative Approaches**

There are other ways to concatenate arrays in JavaScript, such as:

1. **Using `Array.prototype.push()`**: This method appends one or more elements to an existing array.
2. **Using a loop**: A simple loop can also be used to append elements from two arrays.

Here is an example of using `Array.prototype.push()`:```javascript
var arr1 = [1, 2, 3];
var arr2 = [4, 5, 6];

arr1.push(...arr2);
```

Using a loop would require more code and may be less efficient than the spread operator or concatenation:
```javascript
var arr1 = [1, 2, 3];
var arr2 = [4, 5, 6];

for (var i = 0; i < arr2.length; i++) {
    arr1.push(arr2[i]);
}
```
The spread operator is generally considered the most efficient and convenient way to concatenate arrays in modern JavaScript.

Related benchmarks:

test1 array concat vs spred 2000+1000 (version: 0)

Comparing performance of: spred vs concat

Created: 3 years ago by: Guest

Jump to the latest result

spred

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):