Benchmark: Array Splice vs Splice

Script Preparation code:


var arr = Array(10000).fill(1);

Tests:

slice
arr.slice(0, 50)
splice
arr.splice(50)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
splice

Fastest: N/A

Slowest: N/A

Latest run results:

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

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I'll break down the provided benchmark and explain what's being tested, compared, and considered.

**Benchmark Overview**

The provided benchmark is designed to compare the performance of two different ways to remove elements from an array in JavaScript: `Array.prototype.splice()` and `Array.prototype.slice()`. The test case creates a large array (10,000 elements) filled with the value 1 and then measures how many times each method can execute within a second.

**Options Compared**

There are only two options being compared:

1. **`arr.splice(50)`**: This method removes the element at index 50 from the array and returns an array of removed elements. It modifies the original array.
2. **`arr.slice(0, 50)`**: This method creates a new array containing all elements up to index 50 (exclusive) from the original array.

**Pros and Cons**

*   **`arr.splice(50)`**:
    *   Pros: Modifies the original array, efficient for removing elements at specific indices.
    *   Cons: Can be slow for large arrays, as it needs to shift all subsequent elements to fill the gap. Additionally, it returns an array of removed elements, which may not be necessary in every use case.
*   **`arr.slice(0, 50)`**:
    *   Pros: Creates a new array with the desired subset of data, which can be more efficient than modifying the original array. It also doesn't require shifting subsequent elements.
    *   Cons: Creates a new array, which can consume more memory and resources.

**Library and Special JS Features**

In this benchmark, there is no explicit library mentioned. However, it's worth noting that some browsers may have built-in optimizations or polyfills for these methods.

The only special feature being tested here is the use of `Array.prototype.splice()` and `Array.prototype.slice()`, which are standard JavaScript array methods.

**Other Alternatives**

If you need to remove elements from an array without modifying it, consider using other methods like:

*   `arr.filter()`: Removes elements that pass a test (in this case, no change would be needed since we're removing all elements).
*   `Array.from(arr).slice(0, 50)`: Creates a new array by converting the original array to an array of primitive values and then slicing it.

If you need to remove elements while preserving the indices of remaining elements, consider using:

*   `arr.filter()` with an index-based approach.
*   `Array.prototype.map()`, `Array.prototype.reduce()`, or other methods that allow for more complex operations on the array data structure.

Related benchmarks:

Array Splice vs Splice (version: 0)

Comparing performance of: slice vs splice

Created: 6 years ago by: Guest

Jump to the latest result

slice

splice

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):