Benchmark: string.at(-1) vs string[string.length-1]

Tests:

at(-1)
const string = "banana_pie"; string.at(-1);
length-1
const string = "banana_pie"; string[string.length-1]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
at(-1)
length-1

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36 Edg/128.0.0.0

Browser/OS: Chrome 128 on Windows

View result in a separate tab

Test name	Executions per second
at(-1)	119131024.0 Ops/sec
length-1	244947072.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one year 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 is comparing two methods to get the last character of a string: `string.at(-1)` and `string[string.length-1]`.

**Options Being Compared**

There are two main options being compared:

1. **`string.at(-1)`**: This method uses the `at()` function introduced in ECMAScript 2019 (ES2020). It returns the nth element of an array, where n is the index passed as a string. In this case, it's used to get the last character of a string.
2. **`string[string.length-1]`**: This method uses string indexing and returns the character at the last index of the string.

**Pros and Cons**

Here are some pros and cons of each approach:

* `string.at(-1)`:
	+ Pros: More readable and intuitive, as it's similar to array indexing.
	+ Cons: Requires ES2020 support, which might not be available in older browsers or environments.
* `string[string.length-1]`:
	+ Pros: Widely supported across older browsers and environments.
	+ Cons: Less readable and more verbose, as it requires string length calculation.

**Library/Feature Used**

The benchmark uses the `at()` function introduced in ECMAScript 2019 (ES2020). This is a new JavaScript feature that allows indexing into arrays and objects using strings. It's used to provide a more modern and expressive way of accessing array elements, but it may not be supported in older browsers or environments.

**Other Considerations**

When testing these two methods, other considerations come into play:

* **Performance**: Measuring the performance difference between `string.at(-1)` and `string[string.length-1]` can help identify which method is more efficient.
* **Readability**: The choice of method can affect code readability. Some developers might prefer `string[at(-1)]` over `string[string.length-1]` due to its more intuitive syntax.

**Alternative Approaches**

Other alternative approaches for getting the last character of a string include:

* Using the `substr()` or `slice()` methods, which return a subset of characters from the original string.
* Using regular expressions (`RegExp.prototype.exec()`).
* Using string concatenation or other workarounds (less common and less efficient).

In summary, the benchmark is comparing two methods for getting the last character of a string: `string.at(-1)` and `string[string.length-1]`. The choice between these options depends on factors like performance, readability, and compatibility with older browsers or environments.

Related benchmarks:

string.at(-1) vs string[string.length-1] (version: 0)

Couple of methods to get the last character of a string

Comparing performance of: at(-1) vs length-1

Created: one year ago by: Guest

Jump to the latest result

at(-1)

length-1

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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