Benchmark: Slice vs Splice vs Shift 231

Script Preparation code:

var array = [1, 2, 3, 4, 5, 6, 7, 8]
var itemsToRemove = 1

Tests:

array.slice()
array = array.slice(1)
array.splice()
array.splice(0, itemsToRemove)
array.shift()
array.shift()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
array.slice()
array.splice()
array.shift()

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and explain what's being tested.

**Benchmark Definition**

The benchmark is designed to compare the speed of three different methods for removing elements from the beginning of an array:

1. `array.slice(1)`: This method creates a new array that includes all elements except the first two.
2. `array.splice(0, itemsToRemove)`: This method removes `itemsToRemove` elements from the beginning of the array and returns them as an array.
3. `array.shift()`: This method removes and returns the first element from the array.

**Options Compared**

The benchmark is comparing the performance of these three methods on a fixed-size array with 9 elements, specifically removing the first 1 or 2 elements.

**Pros and Cons of Each Approach**

* `array.slice(1)`:
	+ Pros: Efficient and concise.
	+ Cons: Creates a new array, which can be memory-intensive for large arrays.
* `array.splice(0, itemsToRemove)`.
	+ Pros: Modifies the original array in-place.
	+ Cons: Can be slower due to the extra operation of removing elements.
* `array.shift()`.
	+ Pros: Simple and efficient for small arrays or when only removing a single element.
	+ Cons: May not be as efficient for larger arrays, as it involves multiple operations.

**Library Used**

There is no library explicitly mentioned in the benchmark definition. However, all three methods use native JavaScript array functions, which means they rely on built-in engine optimizations and do not require any additional libraries to execute.

**Special JS Feature or Syntax**

The benchmark does not mention any special JavaScript features or syntax that would require a specific execution environment or compiler. The code is written in vanilla JavaScript and should run on most modern browsers without issues.

**Other Alternatives**

For removing elements from the beginning of an array, other methods might include:

* `array.pop()`: Removes and returns the last element from the array.
* `array.concat()`: Creates a new array with the first element removed (although this is not exactly what you're looking for).

However, these alternatives are not tested in the provided benchmark.

**Benchmark Preparation Code**

The script preparation code creates an array of 9 elements (`var array = [1, 2, 3, 4, 5, 6, 7, 8]`) and defines a variable to specify the number of items to remove (`var itemsToRemove = 1`). The `itemsToRemove` value is fixed at 1 for all three test cases.

**Individual Test Cases**

Each test case represents one of the three methods being compared:

* `array.slice(1)`: Removes the first 2 elements (using `slice(1)`).
* `array.splice(0, itemsToRemove)`: Removes the specified number of elements from the beginning of the array (using `splice(0, itemsToRemove)`).
* `array.shift()`: Removes and returns the first element from the array (using `shift()`).

The benchmark results show the execution frequency per second for each test case on a specific device running Mobile Safari 16.

Latest run results:

Run details: (Test run date: 8 months ago)

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 16_1_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.1 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 16 on iOS 16.1.1

View result in a separate tab

Test name	Executions per second
array.slice()	5203513.0 Ops/sec
array.splice()	5206802.0 Ops/sec
array.shift()	10478190.0 Ops/sec

Related benchmarks:

Slice vs Splice vs Shift 231 (version: 0)

Compares the speed for removing 2 items from the beginning of an array

Comparing performance of: array.slice() vs array.splice() vs array.shift()

Created: 8 months ago by: Guest

Jump to the latest result

array.slice()

array.splice()

array.shift()

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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