Benchmark: Array.prototype.concat vs spread operator v3

Tests:

Array.prototype.concat
var array = [ "hello", true, 7 ]; var params = [ "goodbye", false, 8 ]; var other = array.concat(params);
spread operator
var array = [ "hello", true, 7 ]; var params = [ "goodbye", false, 8 ]; 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

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the explanation.

**What is tested on the provided JSON?**

The benchmark measures the performance difference between two approaches for concatenating arrays in JavaScript:

1. `Array.prototype.concat()`: The traditional method of concatenating arrays, which creates a new array and copies elements from both input arrays.
2. Spread operator (`...`): A newer feature introduced in ES6 that allows you to concatenate arrays using the spread operator.

**Options compared**

The benchmark compares the performance of these two approaches under the same conditions:

* Same input data: Two arrays, `array` and `params`, containing string elements, booleans, and numbers.
* No modifications or dependencies on other variables.
* Same execution environment.

**Pros and cons of each approach**

* **Array.prototype.concat()**:
	+ Pros:
		- Widely supported and well-documented in the ECMAScript standard.
		- Easy to understand for developers familiar with traditional JavaScript syntax.
	+ Cons:
		- Creates a new array object, which can be memory-intensive if dealing with large datasets.
		- May incur additional overhead due to the creation of the new array.
* **Spread operator (`...`)**:
	+ Pros:
		- More concise and readable syntax compared to `concat()`.
		- Can be more efficient in terms of memory allocation, as it avoids creating a new array object.
		- Supports arrays with a wide range of elements, including those with nested structures (e.g., objects or other arrays).
	+ Cons:
		- May not be supported by older browsers or environments that don't have ES6 support enabled.
		- Requires the use of `...` and the understanding of spread syntax, which can be a learning curve for some developers.

**Library and its purpose**

None mentioned in the benchmark definition. The test uses only native JavaScript features.

**Special JS feature or syntax (if applicable)**

The benchmark uses the ES6 spread operator (`...`) and is likely targeting modern JavaScript environments with ES6 support. This requires knowledge of the latest JavaScript syntax and features, but the use of `...` makes it easier to understand for developers familiar with modern JavaScript development.

**Other alternatives**

In addition to these two approaches, other methods exist for concatenating arrays in JavaScript:

* Using a loop: Iterating through each element of one array and appending it to another.
* Using `Array.prototype.push()`: Adding multiple elements to an existing array using the `push()` method.
* Using libraries like Lodash (specifically, the `concat` function): While not explicitly mentioned, some JavaScript libraries provide optimized implementations for array concatenation.

These alternatives might have varying performance characteristics and trade-offs compared to `Array.prototype.concat()` and the spread operator.

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.45 Safari/537.36

Browser/OS: Chrome 96 on Windows

View result in a separate tab

Test name	Executions per second
Array.prototype.concat	4444271.5 Ops/sec
spread operator	11959625.0 Ops/sec

Related benchmarks:

Array.prototype.concat vs spread operator v3 (version: 0)

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

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

Created: 5 years ago by: Guest

Jump to the latest result

Array.prototype.concat

spread operator

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):