Benchmark: Array => Spread vs concat

Tests:

spread
const arr1 = [1,2,3,4,5,6,7,8,9,10,11,12] const arr2 = [11,12,13,14,15,16,17,18,19,20] return [...arr1, ...arr2]
concat
const arr1 = [1,2,3,4,5,6,7,8,9,10,11,12] const arr2 = [11,12,13,14,15,16,17,18,19,20] return arr1.concat(arr2)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread
concat

Fastest: N/A

Slowest: N/A

Latest run results:

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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 benchmark definition and test cases to understand what is being tested, compared, and their pros and cons.

**Benchmark Definition:**

The benchmark is defined as an array that contains two arrays of numbers, `arr1` and `arr2`. The purpose of this benchmark is to compare the performance of two different methods for concatenating these arrays:

1. Using the spread operator (`...`)
2. Using the `concat()` method.

**Script Preparation Code:**

Since there is no script preparation code provided, we can assume that it's a simple JavaScript snippet that creates and defines the two arrays `arr1` and `arr2`. The exact implementation is not relevant to this analysis.

**Html Preparation Code:**

There is also no html preparation code provided. This suggests that the benchmarking tool only measures the execution time of the JavaScript code, without considering any HTML-related overhead.

**Individual Test Cases:**

The two test cases are identical, with the same `Benchmark Definition` and only a different approach for concatenating the arrays:

1. **"spread"`**: Uses the spread operator (`...`) to concatenate the arrays.
2. **"concat"`**: Uses the `concat()` method to concatenate the arrays.

**Library Used:**

In neither of the test cases is a specific library mentioned. However, it's likely that the benchmarking tool uses a standard JavaScript library or doesn't require any external libraries for its functionality.

**Special JS Feature/ Syntax:**

The use of the spread operator (`...`) in the "spread" test case utilizes a feature introduced in ECMAScript 2015 (ES6). This feature allows array destructuring and spreading, which is a concise way to concatenate arrays. The `concat()` method, on the other hand, has been part of JavaScript for a long time.

**Pros and Cons:**

Here's a brief analysis of the pros and cons of each approach:

1. **Spread Operator (`...`)**:
	* Pros:
		+ Concise and expressive syntax.
		+ Fast execution in modern browsers.
	* Cons:
		+ May not be supported in older browsers or environments.
		+ Can lead to slower performance due to the need for array copying (although this is mitigated by most modern JavaScript engines).
2. **`concat()` Method**:
	* Pros:
		+ Wide support across different browsers and environments.
		+ Generally considered more efficient than spread operator, especially in older browsers or environments with limited resources.
	* Cons:
		+ Less concise syntax compared to the spread operator.
		+ May have slower performance due to array copying.

**Other Alternatives:**

If you wanted to compare other approaches for concatenating arrays, some alternatives could include:

1. Using `Array.prototype.reduce()` method
2. Using a loop with indexing and assignment
3. Utilizing `Array.prototype.push()` method repeatedly
4. Employing other specialized libraries or polyfills (although these are unlikely to provide significant performance differences)

Keep in mind that the choice of approach depends on the specific requirements, constraints, and goals of your project. For this particular benchmark, comparing the spread operator vs. `concat()` method provides a clear and concise example of two common approaches for array concatenation.

Related benchmarks:

Array => Spread vs concat (version: 0)

Comparing performance of: spread vs concat

Created: 6 years ago by: Guest

Jump to the latest result

spread

concat

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):