Benchmark: splice copy vs replace

Script Preparation code:

var arr = [1,2,3,4,5,6,7,8,9];

Tests:

splice 1
function arrayMove(arr, fromIndex, toIndex) { const length = arr.length; const copiedArr = [...arr]; if (fromIndex !== toIndex && length > fromIndex && length > toIndex) { copiedArr.splice(toIndex, 0, copiedArr.splice(fromIndex, 1)[0]); } return copiedArr; } arrayMove(arr, 0, 3)
splice 2
function arrayMove(arr, fromIndex, toIndex) { const length = arr.length; let element = arr[fromIndex]; if (fromIndex !== toIndex && length > fromIndex && length > toIndex) { arr.splice(fromIndex, 1); arr.splice(toIndex + 1, 0, element); } } arrayMove(arr, 0, 3)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
splice 1
splice 2

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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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 definition and test cases.

**Benchmark Definition**

The benchmark measures the performance of two different approaches to achieve an array move operation: `splice copy` vs `splice replace`.

**Script Preparation Code**
```javascript
var arr = [1,2,3,4,5,6,7,8,9];
```
This code creates an array with 9 elements.

**Html Preparation Code**

Since there is no HTML preparation code provided, we can assume that the benchmark script will be executed in a headless browser environment or directly in the JavaScript engine, without any additional DOM manipulation.

**Individual Test Cases**

There are two test cases:

1. **Test Case: "splice 1"**
```javascript
function arrayMove(arr, fromIndex, toIndex) {
  const length = arr.length;
  let element = arr[fromIndex];
  
  if (fromIndex !== toIndex && length > fromIndex && length > toIndex) {
    arr.splice(fromIndex, 1);
    arr.splice(toIndex + 1, 0, element);
  }
  
  return arr;
}

arrayMove(arr, 0, 3);
```
This test case uses a simple `splice` method to move the element at index 0 to index 3.

2. **Test Case: "splice 2"**
```javascript
function arrayMove(arr, fromIndex, toIndex) {
  const length = arr.length;
  let element = arr[fromIndex];
  
  if (fromIndex !== toIndex && length > fromIndex && length > toIndex) {
    arr.splice(fromIndex, 1);
    arr.splice(toIndex + 1, 0, element);
  }
  
  return arr;
}

arrayMove(arr, 0, 3);
```
This test case is identical to the first one, but with a different variable name `element`.

**Pros and Cons of Different Approaches**

The two approaches differ in how they handle the removal and reinsertion of elements.

* **Splice Copy**: This approach creates a copy of the original array using the spread operator (`[...arr]`) and then uses `splice` to move the element. The pros are that it avoids modifying the original array, making it safer for concurrent access or when preserving the original data is important.
* **Splice Replace**: This approach modifies the original array by removing the element at the `fromIndex` and reinserting it at the `toIndex`. The cons are that it modifies the original array, which can lead to unexpected behavior if the original data is not intended to be modified.

**Library: Lodash**

In one of the test cases, a library called Lodash (`_`) is used. Lodash is a popular JavaScript utility library that provides a set of functions for common tasks, such as array manipulation, string formatting, and more.

The use of Lodash in this benchmark may be intended to simulate real-world scenarios where developers often rely on libraries like Lodash to simplify their code and improve performance.

**Special JS Features**

There are no special JavaScript features or syntax used in these benchmarks that would require additional explanation.

**Alternatives**

Other alternatives for implementing array move operations might include:

* Using the `slice` method instead of `splice`
* Using a library like Ramda, which provides a functional programming approach to array manipulation
* Implementing a custom implementation using loops and manual indexing
* Using a Just-In-Time (JIT) compiler or a native image compiler to optimize the performance of the benchmark

These alternatives might be worth exploring for different use cases or scenarios where the `splice` method is not suitable.

Related benchmarks:

splice copy vs replace (version: 0)

splice copy vs replace

Comparing performance of: splice 1 vs splice 2

Created: 3 years ago by: Guest

Jump to the latest result

splice 1

splice 2

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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