Benchmark: Arr clear2 - MeasureThat.net

Tests:

Asign
let arr1 = [0,1,2,3,4,5,6,7,8,9]; arr1 = [];
Set length
let arr2 = [0,1,2,3,4,5,6,7,8,9]; arr2.length = 0;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Asign
Set length

Fastest: N/A

Slowest: N/A

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/126.0.0.0 Safari/537.36

Browser/OS: Chrome 126 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Asign	92586440.0 Ops/sec
Set length	20578932.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark and explain what's being tested, compared, and their pros/cons.

**Benchmark Definition**

The benchmark definition is a JSON object with minimal information:
```json
{
  "Name": "Arr clear2",
  "Description": null,
  "Script Preparation Code": null,
  "Html Preparation Code": null
}
```
This suggests that the benchmark is focused on measuring the performance of JavaScript arrays. However, there's no specific context or description provided.

**Individual Test Cases**

There are two test cases:
```json
[
  {
    "Benchmark Definition": "let arr1 = [0,1,2,3,4,5,6,7,8,9];\r\narr1 = [];",
    "Test Name": "Asign"
  },
  {
    "Benchmark Definition": "let arr2 = [0,1,2,3,4,5,6,7,8,9];\r\narr2.length = 0;",
    "Test Name": "Set length"
  }
]
```
These test cases measure the performance of two different ways to clear or manipulate a JavaScript array:

1. **Asign**: Assigns an empty value (`[]`) to an existing array using the assignment operator (`=`).
2. **Set length**: Sets the `length` property of an existing array to 0.

**Library and Special JS Features**

There are no specific libraries mentioned in the benchmark definition or test cases.

However, it's worth noting that both test cases use a common JavaScript syntax feature: **optional chaining (`?.`) is not used**, but rather the assignment operator (`=`) and property access (`arr.length`).

**Comparison Options**

The two test cases compare the performance of:

1. **Asign**: Assigning an empty value to the array using `arr = []`.
2. **Set length**: Setting the `length` property directly on the array using `arr.length = 0`.

**Pros and Cons**

Here are some pros and cons for each approach:

* **Asign**:
	+ Pros: Simple, straightforward syntax.
	+ Cons: May create a new object reference if `arr1` is not already an empty array (e.g., if it's an object or a non-empty array), leading to garbage collection overhead.
* **Set length**:
	+ Pros: Does not create a new object reference and avoids potential garbage collection issues.
	+ Cons: Requires explicit property access (`arr.length = 0`), which might be slower due to the lookup.

**Other Alternatives**

If you want to test similar scenarios, consider exploring other ways to clear or manipulate arrays:

* Using `splice()` instead of assignment (e.g., `arr.splice(0);`)
* Using a library like Lodash's `unset()` function
* Testing with different array sizes or data types

Keep in mind that these alternatives may change the benchmark results and require adjustments to the test code.

**Considerations**

When running this benchmark, consider the following:

* The performance difference between `arr = []` and `arr.length = 0` is likely due to the way JavaScript engines optimize array operations.
* Garbage collection overhead might be significant for large arrays or in environments with limited memory resources.
* The use of assignment (`arr = []`) vs. property access (`arr.length = 0`) may lead to differences in execution speed, depending on the specific browser and engine implementation.

Feel free to ask if you have any further questions or would like more information on this topic!

Related benchmarks:

Arr clear2 (version: 0)

Comparing performance of: Asign vs Set length

Created: one year ago by: Guest

Jump to the latest result

Asign

Set length

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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