Benchmark: Test concat vs spread operator

Script Preparation code:

var arr1 = ['a', 'b', 'c'];
var arr2 = ['d', 'e', 'f'];

Tests:

concat
var arr = arr1.concat(arr2);
spread
var arr = [...arr1, ...arr2];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
concat
spread

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's dive into explaining what's being tested in this benchmark.

**What is being tested?**

The provided JSON represents a JavaScript microbenchmark that compares the performance of two approaches for concatenating arrays: the `concat()` method and the spread operator (`...`). The test creates two arrays, `arr1` and `arr2`, and then uses each approach to concatenate them into a new array.

**Options compared:**

The benchmark is testing the following options:

1. **Concatenation using the `concat()` method**: This involves calling the `concat()` method on one of the arrays to create a new array with the elements from both arrays.
2. **Concatenation using the spread operator (`...`)**: This involves using the spread operator to concatenate the elements of two arrays into a new array.

**Pros and Cons of each approach:**

1. **Concatenation using the `concat()` method:**
	* Pros:
		+ Can be faster in some cases, as it avoids creating intermediate arrays.
		+ May be more predictable for developers who are familiar with the `concat()` method.
	* Cons:
		+ Creates a new array, which can be slower and use more memory than creating an array with the spread operator.
2. **Concatenation using the spread operator (`...`):**
	* Pros:
		+ Creates a new array with minimal overhead, as it avoids creating intermediate arrays.
		+ Can be faster in many cases, especially for large datasets.
	* Cons:
		+ May require additional browser support (some older browsers may not understand the spread operator).
		+ Can be less predictable for developers who are not familiar with the syntax.

**Library and purpose:**

In this benchmark, there is no explicit library being used. The `concat()` method is a built-in JavaScript method that is supported by all modern browsers. However, if you were to use a library like Lodash or Underscore.js, which provide alternative concatenation methods (e.g., `_.concat()`, `Array.prototype.chain()`), it would likely affect the benchmark results.

**Special JS feature or syntax:**

There are no special JavaScript features or syntaxes being used in this benchmark. The tests only involve basic array operations and built-in JavaScript methods.

**Other alternatives:**

If you were to create an alternative benchmark, you could consider testing other concatenation methods, such as:

* Using `Array.prototype.push()` with multiple elements
* Using a library like Lodash or Underscore.js for concatenation
* Creating arrays using array literal syntax (`[...arr1, ...arr2]`)
* Comparing performance of different data structures (e.g., arrays vs. linked lists)

Keep in mind that the specific alternatives you choose will depend on your testing goals and requirements.

Latest run results:

Run details: (Test run date: 7 years ago)

User agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36

Browser/OS: Chrome 58 on Windows 7

View result in a separate tab

Test name	Executions per second
concat	1814119.0 Ops/sec
spread	1137058.0 Ops/sec

Related benchmarks:

Test concat vs spread operator (version: 0)

Comparing performance of: concat vs spread

Created: 7 years ago by: Guest

Jump to the latest result

concat

spread

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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