Benchmark: test split string

Script Preparation code:

var mock = "class.module.name"

Tests:

[length - 1]
var d = mock.split(".")[mock.length - 1];
at(-1)
var z = mock.split(".").at(-1);
pop
var z = mock.split(".").pop();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
[length - 1]
at(-1)
pop

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/115.0.0.0 Safari/537.36

Browser/OS: Chrome 115 on Windows

View result in a separate tab

Test name	Executions per second
[length - 1]	14017806.0 Ops/sec
at(-1)	22668438.0 Ops/sec
pop	21814410.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**Benchmark Definition JSON and Benchmark Preparation Code**

The provided `Benchmark Definition` JSON defines a simple benchmark that splits a string using different methods. The script preparation code is:
```javascript
var mock = "class.module.name";
```
This is just a placeholder string used for the benchmark, as the actual content doesn't affect the results.

**Individual Test Cases**

There are three individual test cases:

1. `"[length - 1]"`: This test case uses the indexing syntax to access the last element of the array returned by `mock.split(".")`.
2. `"at(-1)"`: This test case uses the `Array.at()` method to access the last element of the array.
3. `"pop()"`: This test case uses the `Array.pop()` method to remove and return the last element of the array.

**What is being tested?**

These three test cases are testing the performance difference between three different ways to access the last element of an array in JavaScript:

* Indexing syntax (`"[length - 1]"`)
* `Array.at()` method (`"at(-1)"`)
* `Array.pop()` method (`"pop()"`)

**Pros and Cons of each approach:**

1. **Indexing syntax**: This is a simple and widely supported way to access array elements. It's also efficient, as it uses a direct index into the array.
	* Pros: Fast, widely supported, easy to read.
	* Cons: Can be brittle if the indexing assumes a specific array length or structure.
2. **Array.at() method**: This method was introduced in ECMAScript 2019 and provides a more expressive way to access array elements. It's also more modern and efficient than indexing syntax for large arrays.
	* Pros: More expressive, efficient, and future-proof than indexing syntax.
	* Cons: Requires modern JavaScript engines (e.g., Chrome 115), may require additional setup in older browsers or environments.
3. **Array.pop() method**: This method is also widely supported but can be less efficient than indexing syntax for accessing individual elements, as it involves removing the last element from the array.
	* Pros: Fast and simple for removing elements from arrays.
	* Cons: Less efficient than indexing syntax for accessing single elements.

**Other considerations:**

* **Browser support**: The benchmark results are reported for Chrome 115 on Desktop (Windows). Other browsers or platforms may exhibit different performance characteristics due to differences in JavaScript engines, optimizations, or caching.
* **Array size and shape**: The benchmark results assume a fixed array length. For larger arrays or dynamic arrays with varying structures, the performance difference between these methods might be more pronounced.

**Alternatives:**

For similar use cases, you might also want to explore other methods for accessing array elements, such as:

* `Array[Length - 1]` (an older syntax)
* Using a library like Lodash's `at()` function
* Implementing your own custom indexing or array manipulation functions

Keep in mind that the performance difference between these methods can be relatively small in many cases, and the choice of method often depends on code readability, maintainability, and the specific use case.

Related benchmarks:

test split string (version: 0)

Comparing performance of: [length - 1] vs at(-1) vs pop

Created: one year ago by: Guest

Jump to the latest result

[length - 1]

at(-1)

pop

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):