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 ]
jQuery merge
var params = [ "hello", true, 7 ]; var other = $.merge([1, 2], params);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.concat
spread operator
jQuery merge

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks.

**Benchmark Overview**

The provided benchmark compares three ways to concatenate arrays in JavaScript:

1. `Array.prototype.concat()`
2. The new ES6 spread operator (`...`)
3. jQuery's `$`.merge()` method (for older browsers that don't support the spread operator)

**Test Cases**

Each test case consists of a script preparation code and a test name.

* Test Case 1: "Array.prototype.concat"
```javascript
var params = [ "hello", true, 7 ];
var other = [ 1, 2 ].concat(params);
```
This test creates an array `params` with three elements and concatenates it with another array `[1, 2]` using the `concat()` method.

* Test Case 2: "spread operator"
```javascript
var params = [ "hello", true, 7 ];
var other = [ 1, 2, ...params ];
```
This test creates an array `params` with three elements and uses the spread operator (`...`) to concatenate it with another array `[1, 2]`.

* Test Case 3: "jQuery merge"
```javascript
var params = [ "hello", true, 7 ];
var other = $.merge([1, 2], params);
```
This test creates an array `params` with three elements and uses jQuery's `$`.merge()` method to concatenate it with another array `[1, 2]`.

**Options Compared**

The benchmark compares the performance of these three methods:

* `Array.prototype.concat()`: a traditional way to concatenate arrays
* Spread operator (`...`): a new ES6 feature introduced in JavaScript
* jQuery's `$`.merge()` method: an older method for concatenating arrays

**Pros and Cons**

Here are some pros and cons of each approach:

* `Array.prototype.concat()`:
	+ Pros: widely supported, easy to use, no dependencies
	+ Cons: can be slow for large arrays, may not be optimized for modern browsers
* Spread operator (`...`):
	+ Pros: concise, efficient, widely supported in modern browsers
	+ Cons: only supported in JavaScript 2015 and later, may cause compatibility issues with older browsers
* jQuery's `$`.merge()` method:
	+ Pros: widely supported across browsers, easy to use
	+ Cons: adds dependencies (jQuery), not optimized for performance

**Library Usage**

The benchmark uses the jQuery library for its `$`.merge()` method. This is likely due to the fact that older browsers may not support the spread operator or `Array.prototype.concat()`, and this method provides a compatible alternative.

**Special JavaScript Feature or Syntax**

None of the test cases use any special JavaScript features or syntax beyond what's been introduced in recent versions (e.g., ES6).

**Other Alternatives**

If you're interested in exploring other alternatives, here are some options:

* Using `Array.prototype.push()` instead of `concat()`
* Utilizing native WebAssembly (WASM) arrays for performance-critical benchmarks
* Investigating alternative libraries or frameworks that optimize array concatenation

Keep in mind that the choice of approach often depends on your specific use case, performance requirements, and target audience.

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.139 Safari/537.36

Browser/OS: Chrome 66 on Mac OS X 10.13.4

View result in a separate tab

Test name	Executions per second
Array.prototype.concat	6202089.0 Ops/sec
spread operator	5213570.0 Ops/sec
jQuery merge	1949868.8 Ops/sec

Related benchmarks:

Array.prototype.concat vs spread operator (version: 1)

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

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

Created: 8 years ago by: Registered User

Jump to the latest result

Array.prototype.concat

spread operator

jQuery merge

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):