Benchmark: Empty array: Splice vs Shift

Script Preparation code:

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

Tests:

array.splice()
array.splice(0)
array.shift()
while (array.length > 0) array.shift();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

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

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:132.0) Gecko/20100101 Firefox/132.0

Browser/OS: Firefox 132 on Windows

View result in a separate tab

Test name	Executions per second
array.splice()	11886625.0 Ops/sec
array.shift()	651749312.0 Ops/sec

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

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 defined in the `Script Preparation Code` field, which contains an array initialization statement: `var array = [1, 2, 3, 4, 5, 6, 7, 8]`. This creates a large array with 8 elements. The benchmark compares the performance of two ways to remove all items from the beginning of this array:

1. Using `array.splice(0)`: This method removes all elements from the beginning of the array and returns an array with no elements.
2. Using `while (array.length > 0) array.shift();`: This method uses a while loop to repeatedly remove the first element from the array until it's empty.

**Options being compared**

The two options are:

1. **`array.splice(0)`**: This is a native JavaScript function that modifies the original array and returns an empty array.
2. **`while (array.length > 0) array.shift();`**: This is a custom implementation using a while loop and the `shift()` method, which removes the first element from the array without modifying it.

**Pros and Cons**

Here are some pros and cons of each approach:

1. **`array.splice(0)`**
	* Pros:
		+ Native JavaScript function, well-maintained, and optimized.
		+ Fast performance, as it modifies the original array in-place.
	* Cons:
		+ Modifies the original array, which might be undesirable in some cases.
		+ Can throw an error if the array is not long enough to remove elements from.
2. **`while (array.length > 0) array.shift();`**
	* Pros:
		+ Does not modify the original array, preserving its contents.
		+ Can be more predictable and reliable in certain scenarios.
	* Cons:
		+ Requires manual loop management, which can lead to errors if not implemented correctly.
		+ Might have slower performance compared to `splice(0)` due to the overhead of the while loop.

**Library/Function usage**

The benchmark uses no external libraries or functions besides JavaScript's built-in `Array` methods and operators. The custom implementation in the second test case uses only the `Array.prototype.shift()` method, which is also a native JavaScript function.

**Special JS feature/syntax**

There are no special JavaScript features or syntaxes used in this benchmark. It only relies on standard JavaScript language constructs and built-in functions.

**Other alternatives**

If you wanted to implement an alternative approach to remove all items from the beginning of an array, some other options could be:

1. Using `Array.prototype.slice(0)` and then setting the resulting array to `null` or another empty value.
2. Using a more complex loop structure that iterates over the array elements manually.
3. Utilizing a library like Lodash's `rest()` function, which returns an array with all elements removed.

However, it's worth noting that these alternatives might not provide significant performance improvements and might even introduce additional complexity or errors compared to using native JavaScript functions like `splice(0)` or `shift()`.

Related benchmarks:

Empty array: Splice vs Shift (version: 0)

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

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

Created: 2 months ago by: Guest

Jump to the latest result

array.splice()

array.shift()

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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