Benchmark: Slice vs Splice vs Shift for 1 item

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

Latest run results:

Run details: (Test run date: 12 days ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Windows

View result in a separate tab

Test name	Executions per second
array.slice()	5727531.0 Ops/sec
array.splice()	30240254.0 Ops/sec
array.shift()	54843328.0 Ops/sec

Autogenerated LLM Summary (model gemma2:9b, generated 2 months ago):

LLMs can make mistakes. Check important info.

This benchmark compares the performance of three methods for removing one item from the beginning of an array in JavaScript:

* **`array.slice(1)`**: This method creates a new array containing all elements of the original array starting from the second element (index 1). It leaves the original array unchanged.

* **`array.splice(0, 1)`**: This method modifies the original array by removing one element at index 0 (the first element). The `1` specifies the number of elements to remove.

* **`array.shift()`**: This method also modifies the original array by directly removing the first element and returning that element.

**Pros and Cons:**

* **`slice()`**:  
    * **Pros**: Doesn't modify the original array, preserving its state.  
    * **Cons**: Creates a new array, which can be memory-intensive for large arrays. It might be slower than `splice()` or `shift()`.

* **`splice()`**: 
    * **Pros**: Modifies the original array in place, potentially saving memory. Can remove multiple elements at once by changing the second argument.  
    * **Cons**: Slightly slower than `shift()` due to more complex operations.

* **`shift()`**:  
    * **Pros**: Fastest method as it directly modifies the array and doesn't create new arrays. 
    * **Cons**: Only removes one element at a time. Modifies the original array.

**Other Considerations:**

The choice between these methods depends on your specific use case:

* If you need to keep the original array intact, use `slice()`.
* For modifying the array and efficiency, `shift()` is generally preferred for removing single elements. 
* `splice()` offers more flexibility for removing multiple elements or inserting new ones at a specific position within the array.

**Alternatives:**

For truly large arrays, consider using libraries like Lodash or Ramda which often provide optimized versions of these common array operations.

Related benchmarks:

Slice vs Splice vs Shift for 1 item (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: one year 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 Summary (model gemma2:9b, generated 2 months ago):