Benchmark: Array.prototype.concat vs spread operator. ddddjj

Tests:

Array.prototype.concat
var params = Array.from({ length: 5000 }).map((_, i) => i) var other = [ 1, 2 ].concat(params);
spread operator
var params = Array.from({ length: 5000 }).map((_, i) => i) var other = [ 1, 2, ...params ]

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Suite status: <idle, ready to run>

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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 dive into the world of JavaScript microbenchmarks.

**Benchmark Definition**
The benchmark is designed to compare two approaches for concatenating arrays in JavaScript:

1. `Array.prototype.concat()`
2. The new ES6 spread operator (`...`)

**Options Compared**

* `Array.prototype.concat()` : This method takes an array as an argument and returns a new array with the elements of the original array concatenated.
* Spread operator (`...`): This operator is used to expand an array into individual elements, which can be used to concatenate arrays.

**Pros and Cons**

* `Array.prototype.concat()`: Pros:
	+ Well-established method with good performance.
	+ Can handle large arrays efficiently.
	Cons:
	+ Requires a separate array as an argument, which can lead to additional memory allocation.
	+ May have slower performance compared to the spread operator for small arrays.
* Spread operator (`...`): Pros:
	+ Efficient and fast, especially for small arrays.
	+ Reduces memory allocation, making it suitable for large arrays.
	Cons:
	+ Requires modern JavaScript engines that support the spread operator.
	+ Can be less readable for beginners.

**Library and Special JS Feature**
In this benchmark, there is no library being used. However, if we look at the `Benchmark Definition` JSON, we see that `Array.from()` is being used to create an array with 5000 elements. This method was introduced in ECMAScript 2015 (ES6) as a way to create an array from an iterable.

**Other Considerations**

* The benchmark measures the performance of both approaches on a single array, but in real-world scenarios, you might be concatenating multiple arrays.
* The benchmark is run on a desktop platform with Chrome 94 browser, which supports modern JavaScript features like the spread operator. If you were to run this benchmark on an older browser or platform, you might see different results.

**Alternative Approaches**

If you need to concatenate arrays in JavaScript, here are some alternative approaches:

* Using `Array.prototype.concat()`: This is a well-established method that works well for most use cases.
* Using the spread operator (`...`): As mentioned earlier, this approach is efficient and fast, especially for small arrays. However, it requires modern JavaScript engines to support it.
* Using `Array.prototype.push()`: You can use `push()` to add elements to an array without creating a new one, which can be more memory-efficient than concatenating two arrays.

In summary, the benchmark compares two approaches for concatenating arrays in JavaScript: `Array.prototype.concat()` and the spread operator (`...`). The spread operator is efficient and fast, but requires modern JavaScript engines.

Related benchmarks:

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

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

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

Created: 4 years ago by: Guest

Jump to the latest result

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):