Benchmark: array spread vs array concat

Tests:

array concat
var params = [1, 2, 3]; var other = [1, 2]; var array = params.concat(other);
array spread
var params = [1, 2, 3]; var other = [1, 2]; var array = [...params, ...other];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
array concat
array spread

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's break down the provided benchmark and its test cases.

**Benchmark Definition**

The benchmark is defined by a JSON object that provides some basic information about the benchmark:

* `Name`: The name of the benchmark, which in this case is "array spread vs array concat".
* `Description`: An empty string, indicating no description for this benchmark.
* `Script Preparation Code` and `Html Preparation Code`: Empty strings, suggesting that these are not needed for this benchmark.

**Test Cases**

The benchmark consists of two test cases:

1. **Array Concatenation**: This test case uses the `concat()` method to concatenate two arrays:
```javascript
var params = [1, 2, 3];
var other = [1, 2];
var array = params.concat(other);
```
2. **Array Spreading**: This test case uses the spread operator (`...`) to create a new array by spreading the elements of `params` and `other`:
```javascript
var params = [1, 2, 3];
var other = [1, 2];
var array = [...params, ...other];
```
**Library Used**

Neither of these test cases uses any external libraries. The `concat()` method is a built-in JavaScript function, and the spread operator (`...`) was introduced in ECMAScript 2015 (ES6).

**Special JS Features or Syntax**

The spread operator (`...`) is a relatively recent feature introduced in ES6, which allows for more concise array creation. While not new to modern JavaScript development, it might still require some explanation to developers without extensive knowledge of the language.

**Pros and Cons of Different Approaches**

Here are some pros and cons of each approach:

* **Array Concatenation (`concat()` method)**:
	+ Pros: Widely supported, easy to understand, and has been part of JavaScript for a long time.
	+ Cons: Can be slower due to the need to create a new array object and concatenate elements.
* **Array Spreading (`...` operator)**:
	+ Pros: More concise, faster, and can be more efficient in some cases.
	+ Cons: Less widely supported in older browsers or environments, might require explanation for less experienced developers.

**Other Alternatives**

If you wanted to create an array by concatenating two arrays, you could also use the `Array.prototype.push()` method:
```javascript
var params = [1, 2, 3];
var other = [1, 2];
params.push(...other);
```
Alternatively, you could use the `Array.prototype.reduce()` method to concatenate arrays:
```javascript
var params = [1, 2, 3];
var other = [1, 2];
var array = params.reduce((acc, current) => [...acc, current], []);
```
However, these alternatives are less common and might not be as efficient or readable as the spread operator.

Overall, the benchmark provides a simple and concise way to compare the performance of two common JavaScript array creation methods.

Related benchmarks:

array spread vs array concat (version: 0)

Comparing performance of: array concat vs array spread

Created: 6 years ago by: Registered User

Jump to the latest result

array concat

array spread

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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