Benchmark: Array.slice(-1) vs Array.At(-1) Teste Pro Eduzeira

Script Preparation code:

const array = [1,2,3,4,5,6,7,8,9,10,11,12,13];

Tests:

array.at(-1);
const array = [1,2,3,4,5,6,7,8,9,10,11,12,13]; array.at(-1);
array.slice(-1);
const array = [1,2,3,4,5,6,7,8,9,10,11,12,13]; array.slice(-1);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
array.at(-1);
array.slice(-1);

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 24 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark.

**Benchmark Definition**

The benchmark is comparing two approaches to access the last element of an array in JavaScript: `Array.at(-1)` and `Array.slice(-1)`. The purpose of this benchmark is to determine which approach is faster on a specific test case, as specified in the "Script Preparation Code".

**Options Compared**

There are only two options being compared:

1. **`Array.at(-1)`**: This method uses the `at()` method to access an element at a specified index. In this case, the negative of the index `-1` is used to get the last element.
2. **`Array.slice(-1)`**: This method returns a new array containing the last element of the original array.

**Pros and Cons**

*   **`Array.at(-1)`**
    *   Pros:
        *   More concise and expressive syntax compared to `slice()`.
        *   Returns the specified value if the index is out of range, avoiding potential errors.
    *   Cons:
        *   Not supported in older browsers or environments that don't support modern JavaScript features.
*   **`Array.slice(-1)`**
    *   Pros:
        *   Supported in all versions of JavaScript and most browsers.
        *   Allows for more control over the resulting array (e.g., using `slice()` to get a subset).
    *   Cons:
        *   Returns an empty array if the input is null or undefined, which might not be desirable behavior.

**Library and Purpose**

None are explicitly mentioned in this benchmark.

**Special JS Features or Syntax**

The benchmark uses modern JavaScript features such as:

*   `const` (block scope declaration)
*   Template literals (`\r\n`)
*   Arrow functions (`=>`) (although not used here, it's implied)

These features are part of the ECMAScript standard and are widely supported in modern browsers.

**Other Alternatives**

If you want to compare performance with other methods to access the last element of an array:

*   **`array[array.length - 1]`**: This uses direct indexing on the array, which is equivalent to `Array.slice(-1)`. However, it's generally considered less readable and might not be as efficient in some cases.
*   **`Object.keys(array)[-1]`**: This uses `Object.keys()` to get an array of keys for the object (which is an array), and then takes the last key using indexing. While this works, it's a more complex and slower approach.

For this specific benchmark, only two approaches (`Array.at(-1)` and `Array.slice(-1)`) are being compared.

Latest run results:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36 OPR/112.0.0.0 (Edition Yx 05)

Browser/OS: Opera 112 on Windows

View result in a separate tab

Test name	Executions per second
array.at(-1);	221482864.0 Ops/sec
array.slice(-1);	65879152.0 Ops/sec

Related benchmarks:

Array.slice(-1) vs Array.At(-1) Teste Pro Eduzeira (version: 0)

Array.slice(-1) vs Array.At(-1)

Comparing performance of: array.at(-1); vs array.slice(-1);

Created: one year ago by: Guest

Jump to the latest result

array.at(-1);

array.slice(-1);

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 24 days ago):