Benchmark: Slice vs Splice vs Shiftxxxxxx

Script Preparation code:

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

Tests:

array.slice()
array = [1, 2, 3, 4, 5, 6, 7, 8].slice(1)
array.splice()
array.splice(0, itemsToRemove)
array.shift()
for (let i = 0 ; i < itemsToRemove ; i++) 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:

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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 and its test cases.

**Benchmark Overview**

The benchmark compares the speed of three different approaches to remove two items from the beginning of an array: `slice()`, `splice()`, and `shift()`. The arrays are created with 8 elements, and 2 elements are removed using each approach.

**Library and Special Features**

* None mentioned in this specific benchmark.
* However, it's worth noting that JavaScript arrays use a dynamic length mechanism, which means that when an element is removed, the array's length decreases by 1. This might affect performance, but it's not explicitly addressed in this benchmark.

**Approaches Compared**

The three approaches compared are:

1. **`array.slice(1)`**: This method creates a new array with elements from index 1 to the end of the original array, effectively removing the first two elements.
2. **`array.splice(0, 2)`**: This method removes the specified number of elements from the beginning of the array, in this case, 2 elements.
3. **`for (let i = 0; i < 2; i++) array.shift()`**: This approach uses a loop to remove each element individually using the `shift()` method.

**Pros and Cons**

* **`array.slice(1)`**:
	+ Pros: Creates a new array with minimal overhead, efficient in terms of memory usage.
	+ Cons: Requires creating a new array, which can be expensive in some cases.
* **`array.splice(0, 2)`**:
	+ Pros: Removes elements from the original array, can modify the original data.
	+ Cons: Modifies the original array, can be slower than `slice()` due to the overhead of removing elements.
* **`for (let i = 0; i < 2; i++) array.shift()`**:
	+ Pros: Modifies the original array, simple and straightforward implementation.
	+ Cons: Requires multiple iterations through the loop, which can be slower than `slice()` or `splice()`.

**Other Alternatives**

* Other approaches to remove elements from an array include using `array.concat().slice(2)` (more expensive than `slice()`), or using a more complex algorithm like `array.map((_, i) => i > 0 ? ... : null)`. However, these alternatives are not directly comparable in this benchmark.

**Benchmark Interpretation**

The benchmark measures the execution speed of each approach. The results indicate that:

* `array.slice(1)` is the fastest method.
* `array.splice(0, 2)` is slower than `slice()`, but faster than the loop-based approach (`for (let i = 0; i < 2; i++) array.shift()`).
* The loop-based approach is the slowest.

Keep in mind that this benchmark only tests these three specific approaches and does not account for other factors that might affect performance, such as JavaScript engine optimizations or array size.

Related benchmarks:

Slice vs Splice vs Shiftxxxxxx (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: 2 years ago by: Guest

Jump to the latest result

array.slice()

array.splice()

array.shift()

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):