Benchmark: array.splice vs array.length

Script Preparation code:

var arr1=[0,1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9]

Tests:

array.splice
arr1.splice(0,10)
array.length
arr1.length = 10

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
array.splice
array.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/114.0.0.0 YaBrowser/23.7.0.2562 Yowser/2.5 Safari/537.36

Browser/OS: Yandex Browser 23 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
array.splice	19381842.0 Ops/sec
array.length	14924950.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON data and explain what's being tested in the benchmark.

**Benchmark Definition**

The benchmark is defined by a single JSON object with three properties:

* `Name`: The name of the benchmark, which is "array.splice vs array.length".
* `Description`: An empty string, indicating that there is no detailed description for this benchmark.
* `Script Preparation Code` and `Html Preparation Code`: These two properties contain JavaScript code that prepares the test environment. In this case, only `Script Preparation Code` is provided, which defines an array `arr1` with 32 elements.

**Individual Test Cases**

The benchmark consists of two individual test cases:

* `Test Case 1: "array.splice"`. This test case calls the `splice()` method on the `arr1` array, removing the first 10 elements. The test name is "array.splice".
* `Test Case 2: "array.length"` . This test case assigns a new value to the `length` property of the `arr1` array, setting it to 10. However, the actual code executed by this test case is likely a no-op, as assigning a new value to an array's length doesn't actually modify its contents.

**Library Usage**

There is no explicit library usage in this benchmark.

**Special JavaScript Features or Syntax**

None are mentioned in the provided JSON data.

Now, let's discuss the options being compared and their pros and cons:

**Option 1: `arr1.splice(0,10)`**

* **Pros**: This option removes the first 10 elements from the array, which can be useful for testing array manipulation techniques.
* **Cons**: Splicing an array can be slow and inefficient, especially when dealing with large arrays. The JavaScript engine needs to update the internal node array, which can lead to performance overhead.

**Option 2: `arr1.length = 10`**

* **Pros**: Assigning a new value to an array's length is a simple and efficient operation that doesn't modify the actual elements in the array.
* **Cons**: This test case may not accurately represent the behavior of arrays, as setting the length doesn't change the existing elements.

**Other Considerations**

The benchmark seems to be testing two different approaches to manipulating arrays: removing elements using `splice()` and modifying the array's length. The use of a large array (`arr1`) provides enough memory to test the performance impact of these operations.

If you wanted to add more test cases or explore alternative scenarios, some possibilities could include:

* Testing the performance of other array methods (e.g., `push()`, `pop()`, `indexOf()`).
* Examining the behavior of arrays in different browsers or environments.
* Adding additional constraints or variations to the tests (e.g., modifying the size of the array, adding more elements before splicing).

Overall, this benchmark provides a good starting point for comparing the performance of two common array manipulation techniques.

Related benchmarks:

array.splice vs array.length (version: 0)

Comparing performance of: array.splice vs array.length

Created: 2 years ago by: Guest

Jump to the latest result

array.splice

array.length

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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