Benchmark: Array pop vs at - MeasureThat.net

Script Preparation code:

var arr1 = [0,1,2,3,4,5,6,7,8,9];
var arr2 = [];

function getLastPop(arr) {
  return arr.pop();
}

function getLastAt(arr) {
  return arr.at(-1);
}

Tests:

pop
getLastPop(arr1); getLastPop(arr1); getLastPop(arr2);
at
getLastAt(arr1); getLastAt(arr1); getLastAt(arr2);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
pop
at

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 7 days ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36

Browser/OS: Chrome 130 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
pop	2743179.0 Ops/sec
at	2790643.5 Ops/sec

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.

**Benchmark Overview**

The benchmark compares two approaches for accessing the last element of an array:

1. `getLastPop` method: This function uses the `pop()` method to remove and return the last element from the array, effectively removing the element from the array.
2. `getLastAt` method: This function uses the `at(-1)` method to access the last element of the array without modifying it.

**Options Compared**

The two options being compared are:

* `getLastPop(arr1)`: Removes and returns the last element from `arr1`.
* `getLastPop(arr2)`: Removes and returns the last element from an empty array `arr2`. This is likely done to test the performance of removing an element from a non-empty array.
* `getLastAt(arr1)`: Returns the last element of `arr1` without modifying it.
* `getLastAt(arr2)`: Returns the last element of `arr2` without modifying it. This is likely done to test the performance of accessing an empty array.

**Pros and Cons**

* **`getLastPop` method:**
	+ Pros:
		- Efficient for removing elements from arrays, as it only requires a single operation.
	+ Cons:
		- May not be suitable when you need to access elements without modifying the array.
		- Can be slower than `at(-1)` for accessing large arrays.
* **`getLastAt` method:**
	+ Pros:
		- Fast and efficient for accessing elements without modifying the array.
		- Suitable for most use cases where you need to access an element without removing it.
	+ Cons:
		- May not be suitable when you need to remove elements from arrays.
		- Can be slower than `pop()` for removing elements.

**Library: `at()` method**

The `at(-1)` method is a part of the JavaScript ECMAScript standard, and it allows you to access an element at a specific index without modifying the array. The `-1` index refers to the last element of the array.

**Special JS Feature/Syntax**

There doesn't seem to be any special or experimental JavaScript features or syntax being tested in this benchmark. Both `at(-1)` and `pop()` methods are standard and widely supported.

**Other Alternatives**

If you need to access elements from an array without modifying it, other alternatives like using indexing (`arr[arr.length - 1]`) or slicing (`arr.slice(-1)`) might be suitable. However, these approaches may not be as efficient as `at(-1)` for large arrays.

For removing elements from arrays, other alternatives like using the `splice()` method or a library like Lodash's `removeAt()` function might be more convenient and efficient.

Related benchmarks:

Array pop vs at (version: 0)

Comparing pop-push method vs last index check for an array element

Comparing performance of: pop vs at

Created: 2 years ago by: Guest

Jump to the latest result

pop

at

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):