Benchmark: spread vs concat vs unshift vs aaa

Script Preparation code:

var array = [1,2,3];

Tests:

123 push 0
array.unshift(0);
arrayConcat123
array = array.concat([0])
arraySpread123
array = [...array, 0]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
123 push 0
arrayConcat123
arraySpread123

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 data.

**Benchmark Definition JSON**

The provided `Benchmark Definition` JSON represents a JavaScript microbenchmark that compares the performance of three different methods to add an element to an array:

1. `unshift()`: adds an element to the beginning of an array
2. `concat()` with an array literal: concatenates two arrays using the spread operator (`...`)
3. `push()` with the spread operator (`[...]`)

The script preparation code initializes an array `array` with three elements: `[1, 2, 3]`.

**Options Compared**

The benchmark compares the performance of these three methods:

1. `unshift()`: adds a single element (0) to the beginning of the array.
2. `concat()` with an array literal: concatenates two arrays using the spread operator (`[...array, 0]`).
3. `push()` with the spread operator: uses the spread operator to add the element 0 to the end of the array.

**Pros and Cons**

Here's a brief overview of each approach:

1. `unshift()`: Pros:
	* Efficient for small arrays or when adding elements to the beginning is common.
	* Simple syntax.
2. `concat()` with an array literal: Pros:
	* Works well for larger arrays or when concatenating multiple arrays.
	* Less memory-intensive than creating a new array and pushing elements.
3. `push()` with the spread operator: Pros:
	* More concise syntax compared to `concat()`.
	* Can be faster for small arrays.

Cons:

1. `unshift()`: Cons:
	* Requires more elements in the array for optimal performance (due to the shifting of elements).
2. `concat()` with an array literal: Cons:
	* Creates a new array, which can lead to increased memory allocation and garbage collection.
3. `push()` with the spread operator: Cons:
	* Only works when adding a single element at the end; more complex syntax for other use cases.

**Library**

There is no explicit library mentioned in the benchmark data. However, it's likely that the microbenchmark framework uses internal libraries or implementations of these methods to execute the tests.

**Special JS Feature or Syntax**

The spread operator (`...`) introduced in ES6 (2015) allows for more concise and expressive array concatenation and creation. This feature is widely supported across modern JavaScript engines.

**Other Alternatives**

If `push()` with the spread operator wasn't allowed, other alternatives could include:

1. Using `array.splice()` to insert an element at a specific position.
2. Creating a new array using `Array.from()` and pushing elements to it.
3. Implementing a custom insertion function for arrays.

Keep in mind that these alternatives would likely have different performance characteristics compared to the original methods tested in this benchmark.

Related benchmarks:

spread vs concat vs unshift vs aaa (version: 0)

spread vs concat vs unshift

Comparing performance of: 123 push 0 vs arrayConcat123 vs arraySpread123

Created: 3 years ago by: Guest

Jump to the latest result

123 push 0

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):