Benchmark: Concat Array - MeasureThat.net

Script Preparation code:

var arr1 = [1,2,3,4,5]
var arr2 = [6,7,8,9,10]

Tests:

Spread Array
myArr = [...arr1, ...arr2]
new Array with Spread
myArr = new Array(...arr1, arr2)
Array Concat
myArr = Array.prototype.concat(arr1, arr2)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Spread Array
new Array with Spread
Array Concat

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 results.

**Benchmark Definition**

The benchmark definition is a JSON object that describes the test case. In this case, we have three test cases:

1. **Concat Array**: This test case creates two arrays `arr1` and `arr2`, and then concatenates them using the spread operator (`...`) to create a new array `myArr`.
2. **Spread Array**: This test case is identical to the first one, but with a different name for the benchmark definition.
3. **new Array with Spread**: This test case creates two arrays `arr1` and `arr2`, and then uses the `new Array()` constructor with the spread operator (`...`) to create a new array `myArr`.

**Options Compared**

The three test cases compare the performance of different approaches for concatenating arrays:

* **Spread Operator (`...`)**: This approach creates a new array by spreading the elements of one or more arrays into a new array.
* **`Array.prototype.concat()`**: This approach uses the `concat()` method to concatenate two arrays and return a new array.

**Pros and Cons**

Here are some pros and cons for each approach:

1. **Spread Operator (`...`)**:
	* Pros:
		+ More concise and expressive syntax.
		+ Can be used with an arbitrary number of arrays.
		+ More efficient than `concat()` in many cases (see below).
	* Cons:
		+ May not be supported in older browsers or environments that don't understand the spread operator.
2. **`Array.prototype.concat()`**:
	* Pros:
		+ Widely supported across modern browsers and environments.
		+ Can be used with arrays of any type, including non-array values.
	* Cons:
		+ More verbose syntax compared to the spread operator.
		+ May not be as efficient as the spread operator in some cases.

**Efficiency**

In general, the spread operator is more efficient than `concat()` because it avoids the overhead of creating a new function call and executing the `concat()` method. However, the performance difference may vary depending on the specific use case and environment. In this benchmark, we can see that all three test cases have similar execution rates, indicating that the performance difference between the spread operator and `concat()` is not significant.

**Library Usage**

None of the test cases use any libraries or external dependencies.

**Special JS Features or Syntax**

The spread operator (`...`) is a modern JavaScript feature introduced in ECMAScript 2015 (ES6). It allows for more concise syntax when working with arrays and other iterable objects. The `new Array()` constructor with the spread operator is also a relatively new feature, but it has gained widespread support across modern browsers and environments.

**Other Alternatives**

If you need to concatenate arrays in JavaScript, some alternative approaches include:

* Using the `Array.prototype.push()` method:
```javascript
var arr1 = [1, 2];
arr1.push(3, 4);
```
This approach is less efficient than the spread operator or `concat()`, but it can be useful for certain use cases.
* Using a library like Lodash's `concat` function:
```javascript
const _ = require('lodash');
var arr1 = [1, 2];
var arr2 = [3, 4];
arr1.concat(arr2);
```
This approach provides more flexibility and utility functions, but it also introduces additional dependencies and overhead.

Related benchmarks:

Concat Array (version: 0)

Comparing performance of: Spread Array vs new Array with Spread vs Array Concat

Created: 7 years ago by: Guest

Jump to the latest result

Spread Array

new Array with Spread

Array Concat

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):