Benchmark: Array.prototype.concat vs spread operator v6

Script Preparation code:

var array = [ "hello", true, 7 ];
var params = [ "goodbye", false, 8 ];

Tests:

Array.prototype.concat
var other = array.concat(params);
spread operator
var other = [ ...array, ...params ]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.concat
spread operator

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Let's dive into the explanation of the provided benchmark.

**Benchmark Definition**

The benchmark compares two approaches to concatenate arrays in JavaScript:

1. `Array.prototype.concat()`: This method concatenates an array with another array (or any other iterable) and returns a new array.
2. The **spread operator v6** (`[ ...array, ...params ]`): This is a newer syntax introduced in ECMAScript 2015 (ES6), which uses the spread operator to expand arrays into separate arguments.

**Options Compared**

The benchmark compares these two approaches for concatenating two arrays:

* `Array.prototype.concat()`
* The spread operator (`[ ...array, ...params ]`)

**Pros and Cons of Each Approach**

1. **`Array.prototype.concat()`**:
	* Pros: Widely supported across browsers, more readable syntax.
	* Cons: Creates a new array object, which can be slower for large datasets.
2. The spread operator (`[ ...array, ...params ]`):
	* Pros: More concise and expressive syntax, potentially faster performance since it avoids the overhead of creating a new array object.
	* Cons: Requires modern browsers that support the ES6 spread operator (which is widely supported now).

**Library and Special JS Features**

In this benchmark, no libraries are explicitly used. However, the use of the spread operator (`[ ...array, ...params ]`) relies on the modern JavaScript feature introduced in ES6.

**Other Considerations**

The performance difference between these two approaches can be significant for large datasets, as creating a new array object using `concat()` might incur additional overhead compared to the spread operator. However, the actual performance impact depends on various factors, such as:

* The size and complexity of the data being concatenated.
* The specific browser and JavaScript engine being used.

**Alternatives**

Other alternatives for concatenating arrays in JavaScript include:

1. Using `Array.prototype.push()` and setting the length property to concatenate two arrays:
```javascript
array = array.concat(params);
```
This approach is less efficient than using the spread operator or `concat()`, but still widely supported.
2. Using a library like Lodash, which provides an optimized implementation of array concatenation: `_concat(array, params)`.

In summary, this benchmark compares two common approaches for concatenating arrays in JavaScript: `Array.prototype.concat()` and the spread operator (`[ ...array, ...params ]`). The latter is generally considered more concise and potentially faster, but requires modern browsers that support ES6 features.

Related benchmarks:

Array.prototype.concat vs spread operator v6 (version: 0)

Compare the new ES6 spread operator with the traditional concat() method

Comparing performance of: Array.prototype.concat vs spread operator

Created: 6 years ago by: Guest

Jump to the latest result

Array.prototype.concat

spread operator

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):