Benchmark: Slice vs Pop return value

Script Preparation code:

var arr = [1, 3, 5, 11, 13];

Tests:

Slice
arr.slice(-1)[0];
Pop
arr.pop();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Slice
Pop

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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**What is being tested?**

The provided benchmark compares the performance of two approaches to remove and return the last element from an array in JavaScript:

1. `arr.slice(-1)[0];`
2. `arr.pop();`

In both cases, the original array `arr` contains elements `{1, 3, 5, 11, 13}`.

**Options compared**

The two options being tested are:

* `slice(-1)[0]`: This method creates a new array with a single element, the last one from the original array. The `[0]` index is used to extract the value of this element.
* `pop()`: This method removes and returns the last element from the original array.

**Pros and Cons**

* **Slice approach**
	+ Pros: Efficient for large arrays since it creates a new array with only one element, avoiding the need to traverse the entire array. It's also more flexible if you want to return multiple elements or use it as an index.
	- Cons: Creates a new object in memory, which can lead to performance issues in terms of garbage collection and potential allocation errors. Additionally, it requires indexing (`[0]`) to extract the desired value.
* **Pop approach**
	+ Pros: Simple, efficient, and memory-efficient since it modifies the original array without creating any intermediate objects. It's also a native method that is well-supported by most modern browsers.
	- Cons: Only removes and returns the last element, which may not be suitable for all scenarios where you need to access or manipulate other elements in the array.

**Library usage**

In this benchmark, there are no libraries used beyond the built-in JavaScript `Array` methods. However, note that some implementations of `pop()` might use a more complex algorithm under the hood, but it's not specific to any external library.

**Special JS feature or syntax**

There is no special JavaScript feature or syntax mentioned in this benchmark. The code snippets provided are straightforward and do not utilize any advanced features.

**Other alternatives**

In theory, there are other ways to remove and return the last element from an array, such as:

* Using `Array.prototype.reverse()` followed by `[0]`, which reverses the entire array but returns only the first (and in this case, only) element.
* Utilizing a simple loop to iterate through the array elements and keep track of the last one.
* Employing a more efficient algorithm like [this](https://jsperf.com/array-pop-vs-slice), although this would likely involve additional setup and may not be as straightforward as using built-in methods.

However, these alternatives are not tested in this specific benchmark and would require further modifications to create meaningful comparisons.

Related benchmarks:

Slice vs Pop return value (version: 0)

Comparing performance of: Slice vs Pop

Created: 3 years ago by: Guest

Jump to the latest result

Slice

Pop

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):