Benchmark: Array.prototype.concat vs spread operator reverse version

Tests:

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

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Test case name	Result
Array.prototype.concat
spread operator

Fastest: N/A

Slowest: N/A

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

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Let's break down the provided JSON and benchmark.

**Benchmark Purpose**

The benchmark is designed to compare two approaches for concatenating arrays in JavaScript: the traditional `Array.prototype.concat()` method and the new ES6 spread operator (`...`). The goal is to measure which approach is faster.

**Options Compared**

Two options are compared:

1. **Traditional `Array.prototype.concat()`**: This method takes an array as an argument and returns a new array that contains all elements from the original array and the provided elements.
2. **ES6 Spread Operator (`...`)**: This operator allows you to extract elements from an array and spread them into a new array.

**Pros and Cons of Each Approach**

1. **Traditional `Array.prototype.concat()`**
	* Pros:
		+ Well-established method with good performance in older browsers.
		+ Easy to understand and use, especially for those familiar with the traditional way of concatenating arrays.
	* Cons:
		+ Can be slower than the spread operator due to the overhead of creating a new array object.
2. **ES6 Spread Operator (`...`)**
	* Pros:
		+ Faster performance compared to `concat()` since it avoids creating a new array object.
		+ More concise and expressive syntax, making it easier to read and write code.
	* Cons:
		+ Requires support for ES6 in the browser or environment. If not supported, alternative approaches must be used.

**Library Usage**

None of the test cases use any external libraries.

**Special JS Features/Syntax**

The benchmark uses two special features:

1. **Spread Operator (`...`)**: Introduced in ECMAScript 2015 (ES6), this operator allows you to extract elements from an array and spread them into a new array.
2. **Concatenation**: The `concat()` method is used to concatenate arrays, which was the traditional way of joining arrays in JavaScript before the introduction of the spread operator.

**Other Considerations**

When choosing between these two approaches, consider the following factors:

* Performance: If speed is crucial, use the ES6 spread operator. Otherwise, `concat()` might be sufficient.
* Code readability and maintainability: Choose the approach that makes your code easier to understand and write.
* Browser compatibility: Make sure the chosen method works across different browsers, especially older ones.

**Alternatives**

If the spread operator is not supported in the target environment, alternative approaches can be used:

1. **`Array.prototype.push()`**: Instead of `concat()`, you can push elements onto the end of the original array.
2. **`.slice()`**: You can use `.slice()` to create a shallow copy of the original array and then push new elements onto it.

For example, instead of using the spread operator:
```javascript
var params = [ 'hello', true, 7 ];
var other = [ ...params, 1, 2 ]; // not supported in this browser
```
You can use `push()` or `.slice()` like this:
```javascript
var params = [ 'hello', true, 7 ];
params.push(1, 2); // using push()
// or
var other = params.slice().concat([ 1, 2 ]); // using slice() and concat()
```
Keep in mind that these alternatives may have different performance characteristics compared to the spread operator.

Related benchmarks:

Array.prototype.concat vs spread operator reverse version (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

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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):