Benchmark: Array.prototype.concat vs spread operato

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

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:95.0) Gecko/20100101 Firefox/95.0

Browser/OS: Firefox 95 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
Array.prototype.concat	9125871.0 Ops/sec
spread operator	10284909.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what is being tested, compared, and analyzed.

**What is being tested?**

The benchmark compares two approaches to concatenate arrays in JavaScript:

1. **`Array.prototype.concat()`**: A traditional method that uses the `concat()` function to merge two arrays.
2. **Spread operator (`...`)**: A new ES6 feature introduced in 2015, which allows for more concise and expressive array concatenation.

**Options compared**

The benchmark tests both approaches on the same input data:

* For `Array.prototype.concat()`, the code uses:
	+ `var params = [ "hello", true, 7 ];`
	+ `var other = [ 1, 2 ].concat(params);`
* For the spread operator, the code uses:
	+ `var params = [ "hello", true, 7 ]`
	+ `var other = [ 1, 2, ...params ]`

**Pros and Cons of each approach**

**`Array.prototype.concat()`**:

Pros:

* Widely supported across browsers and Node.js versions.
* Easy to understand for developers familiar with traditional array manipulation.

Cons:

* Can be slower due to the overhead of calling a method on an array.
* May not be as expressive or concise as other options.

**Spread operator (`...`)**

Pros:

* More concise and expressive than traditional `concat()` methods.
* Can be faster in modern browsers and Node.js versions that support it.

Cons:

* Requires modern JavaScript features (ES6+) to be supported.
* May have compatibility issues with older browsers or versions of Node.js.

**Other considerations**

Both approaches are suitable for simple array concatenation tasks. However, the spread operator offers a more concise and expressive way to achieve this, making it a popular choice in modern JavaScript development.

**Library/Utility used**

None is explicitly mentioned in the benchmark definition. The tests rely on built-in JavaScript features and do not use any external libraries or utilities.

**Special JS feature/syntax**

The spread operator (`...`) is a special JavaScript feature introduced in ES6 (ECMAScript 2015). It allows for concise array expansion, enabling code like `var other = [ 1, 2, ...params ]` to create new arrays by spreading elements from another array.

**Alternatives**

Other alternatives for concatenating arrays include:

* Using the `push()` method: `arr.push(...[1, 2]);`
* Using the `set()` method (for older browsers that don't support spread): `arr.set(3); arr.set(4);`

Related benchmarks:

Array.prototype.concat vs spread operato (version: 0)

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

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

Created: 3 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 2 months ago):