Benchmark: spread vs concat vs unshift22

Script Preparation code:

var array = [1,2,3];

Tests:

arrayUnshift123
array.slice().unshift(0);
arrayConcat123
array = array.concat([0])
arraySpread123
array = [0, ...array]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
arrayUnshift123
arrayConcat123
arraySpread123

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Let's dive into the explanation of the provided benchmark.

**Benchmark Definition JSON**

The provided benchmark definition is a JSON object that contains information about the test case. Here's what it represents:

* `Name`: The name of the benchmark, which is "spread vs concat vs unshift22".
* `Description`: A brief description of the test case, which explains that it compares the performance of three different approaches: `unshift`, `concat`, and spread operator (`...`).
* `Script Preparation Code`: A JavaScript code snippet that prepares the test array before running the benchmark. In this case, the array is initialized with values `[1, 2, 3]`.
* `Html Preparation Code`: An empty string, indicating that no HTML preparation code is needed for this benchmark.

**Individual Test Cases**

The benchmark consists of three individual test cases, each represented by a JSON object:

1. `arrayUnshift123`:
	* `Benchmark Definition`: A JavaScript code snippet that tests the performance of `unshift(0)` on an array slice.
2. `arrayConcat123`:
	* `Benchmark Definition`: A JavaScript code snippet that tests the performance of `concat([0])` on an array variable.
3. `arraySpread123`:
	* `Benchmark Definition`: A JavaScript code snippet that tests the performance of `[0, ...array]`, using the spread operator to create a new array with the original array's values.

**Options Compared**

The benchmark compares the performance of three different approaches:

1. `unshift(0)`: This approach modifies the original array by adding an element at the beginning.
2. `concat([0])`: This approach creates a new array by concatenating the original array with a single-element array `[0]`.
3. Spread operator (`[0, ...array]`): This approach creates a new array by duplicating each element of the original array.

**Pros and Cons**

Here's a brief analysis of each approach:

1. `unshift(0)`: Pros:
	* Modifies the original array in place.
	* Can be more efficient for large arrays since it avoids creating new arrays.
Cons:
	* May have performance implications if the array is very large, as it needs to shift all elements to make room for the new element.
2. `concat([0])`: Pros:
	+ Creates a new array without modifying the original one.
	+ Can be more predictable and easier to reason about.
Cons:
	+ Creates a new array with additional memory allocation.
	+ May have slower performance due to the creation of a new array.
3. Spread operator (`[0, ...array]`): Pros:
	* Creates a new array without modifying the original one.
	* Can be more efficient for large arrays since it uses a specialized optimization in V8 (the JavaScript engine used by Chrome).
Cons:
	+ May have performance implications if the array is very large, as it needs to allocate additional memory.

**Libraries and Special Features**

None of these test cases rely on any external libraries or special features. They are pure JavaScript operations that can be executed anywhere.

**Other Alternatives**

If you want to compare the performance of other approaches, some alternatives could include:

1. Using `push(0)` instead of `unshift(0)`.
2. Using `slice()` with a negative start index instead of `concat([0])`.
3. Using `Array.prototype.set()` or `Array.prototype.fill()` instead of spread operator (`[0, ...array]`).

Keep in mind that these alternatives may have different performance characteristics and trade-offs, so be sure to test them thoroughly before using them in production code.

Related benchmarks:

spread vs concat vs unshift22 (version: 0)

spread vs concat vs unshift

Comparing performance of: arrayUnshift123 vs arrayConcat123 vs arraySpread123

Created: 3 years ago by: Guest

Jump to the latest result

arrayUnshift123

arrayConcat123

arraySpread123

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):