Benchmark: spread vs concat vs unshift vs splice

Script Preparation code:

var array = [1,2,3];

Tests:

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

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
arrayUnshift123
arrayConcat123
arraySpread123
arraySplice

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Measuring the performance of different JavaScript array manipulation methods is crucial for ensuring efficient code execution. Let's break down what's being tested in this benchmark.

**Benchmark Definition:**
The provided JSON represents a benchmark that compares the performance of four different array manipulation methods:

1. `unshift`: Adds an element to the beginning of an array.
2. `concat`: Concatenates two or more arrays into one.
3. `unshift` (alternative): Similar to `unshift`, but using destructuring syntax (`[0, ...array]`) instead of the traditional method call.
4. `splice`: Removes and returns elements from an array at a specified index.

**Options Compared:**

* **Performance**: The benchmark measures the execution speed of each method in terms of executions per second (EPS).
* **Memory allocation**: Although not explicitly measured, the methods might incur different memory allocations or copies during execution.

**Pros and Cons of Each Approach:**

1. `unshift`:
	* Pros: Can be more efficient than `concat` for large arrays, as it only allocates a single new element.
	* Cons: May involve more overhead due to inserting elements at the beginning of the array.
2. `concat`:
	* Pros: Simple and straightforward, with minimal overhead.
	* Cons: May incur higher memory allocation costs, especially for large arrays.
3. `unshift` (alternative):
	* Pros: Similar performance characteristics to traditional `unshift`, but with a more concise syntax.
	* Cons: Might be less intuitive or readable due to the use of destructuring syntax.
4. `splice`:
	* Pros: Can remove and replace elements in an array, which might be useful in certain scenarios.
	* Cons: May incur higher overhead due to inserting new elements into the existing array.

**Library Usage (none):**
There are no libraries used in this benchmark, so there's no additional overhead or impact from third-party dependencies.

**Special JS Features/ Syntax (none):**

Since none of the tested methods involve special JavaScript features or syntax, there's no need to discuss them further.

**Other Alternatives:**

Some alternative array manipulation methods that might be worth considering include:

* `Array.prototype.push` with `...array`: A more concise way to add elements to an array using the spread operator.
* `Array.prototype.slice()`: Creates a shallow copy of a portion of an array, which can be useful for manipulating arrays in a more predictable manner.

Keep in mind that these alternatives might not be directly comparable to the methods tested in this benchmark, as their performance characteristics and use cases may differ.

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.5060.114 Safari/537.36

Browser/OS: Chrome 103 on Windows

View result in a separate tab

Test name	Executions per second
arrayUnshift123	25816.5 Ops/sec
arrayConcat123	656.6 Ops/sec
arraySpread123	141.7 Ops/sec
arraySplice	7100.7 Ops/sec

Related benchmarks:

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

spread vs concat vs unshift vs splice

Comparing performance of: arrayUnshift123 vs arrayConcat123 vs arraySpread123 vs arraySplice

Created: 2 years ago by: Registered User

Jump to the latest result

arrayUnshift123

arrayConcat123

arraySpread123

arraySplice

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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