Benchmark: Array.prototype.concat vs spread operator_

Tests:

Array.prototype.concat
var params = [ "hello", true, 7 ]; var other = [ 1, 2 ].concat(params);
spread operator
var params = [ "hello", true, 7 ] var other = [ 1, 2, ...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 28 days ago):

LLMs can make mistakes. Check important info.

**Overview of the Benchmark**

The provided JSON represents a JavaScript microbenchmark that compares two approaches for concatenating arrays: the traditional `Array.prototype.concat()` method and the new ES6 spread operator (`...`).

**Options Compared**

The benchmark tests two options:

1. **`Array.prototype.concat()`**: This is the traditional way to concatenate arrays in JavaScript. It creates a new array by copying elements from both input arrays.
2. **Spread Operator (`...`)**: Introduced in ECMAScript 2015, the spread operator allows for more concise and expressive array creation.

**Pros and Cons of Each Approach**

* **`Array.prototype.concat()`**:
	+ Pros:
		- Wide browser support (has been around since ES5)
		- Easy to implement
	+ Cons:
		- Creates a new array, which can lead to performance issues for large datasets.
		- Can be slower due to the overhead of creating a new array object.
* **Spread Operator (`...`)**:
	+ Pros:
		- More concise and readable syntax
		- Does not create a new array, but instead modifies the original array (if used with `Array.prototype.push()` or other methods).
	+ Cons:
		- Requires modern browsers (Chrome 67+) to support.
		- May have performance issues if used incorrectly or with large datasets.

**Library and Special JS Features**

The benchmark does not explicitly use any libraries, but it does utilize the ES6 spread operator (`...`), which is a built-in feature of JavaScript. There are no special JavaScript features or syntax used in this benchmark.

**Other Alternatives**

If you want to explore alternative approaches for array concatenation, consider:

* **`Array.prototype.push()`**: This method modifies the original array by adding elements at the end.
* **`Array.prototype.splice()`**: This method can be used to add multiple elements to an array without modifying it (using `splice(0, 0, ...)`).
* **`Array.from()`** with a spread operator (`...`): This method creates a new array from an iterable object.

Keep in mind that these alternatives may have different performance characteristics and usage scenarios compared to the traditional `Array.prototype.concat()` method and the ES6 spread operator.

Latest run results:

Run details: (Test run date: 6 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36

Browser/OS: Chrome 67 on Windows

View result in a separate tab

Test name	Executions per second
Array.prototype.concat	5433951.0 Ops/sec
spread operator	18519832.0 Ops/sec

Related benchmarks:

Array.prototype.concat vs spread operator_ (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>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):