Benchmark: test concat vs spread+push

Script Preparation code:

var original = [1,2,3,4,5,6,7,8,9,10];
var _new = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'];

Tests:

concat
original = original.concat(_new);
spread+push
original.push(..._new);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
concat
spread+push

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.1:latest, generated 28 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the details of this benchmark.

**What is being tested?**

The benchmark is testing two different approaches to concatenate (join) two arrays (`original` and `_new`) in JavaScript:

1. `concat`: Using the built-in `concat()` method to merge the two arrays.
2. `spread+push`: Using a combination of the spread operator (`...`) and the `push()` method to append elements from one array to another.

**What options are compared?**

In this benchmark, we have two test cases that compare the performance of these two approaches:

* `concat`: Using `original.concat(_new);` to concatenate the arrays.
* `spread+push`: Using `original.push(..._new);` to append elements from `_new` to `original`.

**Pros and Cons of each approach:**

1. **concat()**:
	* Pros: A simple, straightforward method that is easy to understand.
	* Cons: May be slower for large arrays due to the overhead of creating a new array.
2. **spread+push**:
	* Pros: Can be faster than `concat()` for large arrays since it appends elements directly without creating a new array.
	* Cons: Requires knowledge of the spread operator and can be less intuitive.

**Library, special JS feature, or syntax used?**

None specifically mentioned in this benchmark. However, the spread operator (`...`) is used in one of the test cases, which was introduced in JavaScript (ECMAScript 2015) as a way to expand arrays or objects into their individual elements.

**Other considerations and alternatives:**

1. **Array.prototype.push.apply()**: Another alternative approach that uses `push()` with `apply()` method to append elements from one array to another.
2. **Using `forEach()` or `map()`**: While not directly compared in this benchmark, using a loop (e.g., `forEach()` or `map()`) can also be an option for concatenating arrays.

Overall, this benchmark provides insight into the performance differences between two common approaches for concatenating arrays in JavaScript, which can be useful for developers looking to optimize their code.

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.139 Safari/537.36

Browser/OS: Chrome 66 on Mac OS X 10.11.6

View result in a separate tab

Test name	Executions per second
concat	964.4 Ops/sec
spread+push	2384949.2 Ops/sec

Related benchmarks:

test concat vs spread+push (version: 0)

Comparing performance of: concat vs spread+push

Created: 6 years ago by: Guest

Jump to the latest result

concat

spread+push

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.1:latest, generated 28 days ago):