Benchmark: at vs pop - MeasureThat.net

Script Preparation code:

arr = [0, 1, 2, 3]

Tests:

pop
arr.pop()
at
arr.at(-1)
index
arr[arr.length - 1]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
pop
at
index

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested, compared, and considered.

**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The goal is to measure the performance of different approaches for accessing an element in an array using two methods: `at()`, `pop()`, and indexing with square brackets (`[]`).

**Script Preparation Code**

The script preparation code is:
```javascript
arr = [0, 1, 2, 3];
```
This line creates a new JavaScript array `arr` containing four elements.

**Html Preparation Code**

There is no HTML preparation code provided, which means that the benchmark focuses solely on JavaScript performance.

**Individual Test Cases**

The benchmark consists of three test cases:

1. `arr.pop()`: Tests the performance of accessing an element from the end of the array using the `pop()` method.
2. `arr.at(-1)`: Tests the performance of accessing an element from the end of the array using the `at()` method with a negative index.
3. `arr[arr.length - 1]`: Tests the performance of indexing directly into the array using square brackets (`[]`) to access the last element.

**Library and Special Features**

There are no external libraries used in this benchmark, but we do see some special JavaScript features:

* The `at()` method is used to access an element from the end of the array. This method was introduced in ECMAScript 2020 as a new way to access elements at specific indices.
* Negative indexing is supported by both `pop()` and `at()`. This means that if you pass `-1` as the index, it will return the last element of the array.

**Options Compared**

The benchmark compares three approaches for accessing an element from the end of the array:

1. `arr.pop()`: Removes and returns the last element of the array.
2. `arr.at(-1)`: Returns the last element of the array without removing it.
3. Indexing with square brackets (`[]`): Directly accesses the last element of the array using `arr[arr.length - 1]`.

**Pros and Cons**

Here are some pros and cons for each approach:

* `arr.pop()`:
	+ Pros: Simple to use, efficient in terms of performance.
	+ Cons: Removes the last element from the array, which can be a problem if you need to keep the entire array intact.
* `arr.at(-1)`:
	+ Pros: Returns the last element without removing it, which is useful for preserving the original array state.
	+ Cons: Requires support for the new `at()` method, which may not be available in all browsers or environments.
* Indexing with square brackets (`[]`):
	+ Pros: Portable across different browsers and environments, does not require any additional libraries or methods.
	+ Cons: Can be slower than using `pop()` or `at()`, especially for large arrays.

**Other Alternatives**

Some alternative approaches to accessing an element from the end of an array include:

* Using a custom function to access elements at specific indices.
* Using a different data structure, such as a linked list or a stack.
* Avoiding indexing altogether and using other methods, such as `splice()` or `indexOf()`, to remove elements.

However, these alternatives may not be as efficient or convenient as the approaches tested in this benchmark.

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/108.0.0.0 Safari/537.36

Browser/OS: Chrome 108 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
pop	12741862.0 Ops/sec
at	12691457.0 Ops/sec
index	4949846.5 Ops/sec

Related benchmarks:

at vs pop (version: 0)

Comparing performance of: pop vs at vs index

Created: one year ago by: Guest

Jump to the latest result

pop

at

index

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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