Benchmark: splice vs slice - MeasureThat.net

Tests:

slice
const arr = new Array(100).fill('').map((_,i) => i); const r1 = { a:'123' }; const r2 = { b:'123' }; const res = [ ...arr.slice(0, 2), r1, ...arr.slice(2, 5), r2, ...arr.slice(5), ]
splice
const arr = new Array(100).fill('').map((_,i) => i); const r1 = { a:'123' }; const r2 = { b:'123' }; const res = [...arr]; res.splice(2,0,r1); res.splice(5,0,r2);

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):

LLMs can make mistakes. Check important info.

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**Benchmark Definition**

The provided JSON represents a benchmark definition, which includes:

* `Name`: The name of the benchmark, which is "splice vs slice".
* `Description`: An empty string, indicating that no description is available for this benchmark.
* `Script Preparation Code` and `Html Preparation Code`: Empty strings, indicating that no special preparation code is required.

**Individual Test Cases**

There are two test cases:

1. **"slice"`**
	* The benchmark definition creates an array of 100 elements using the `Array.prototype.fill()` method and a map function.
	* It then uses the spread operator (`...`) to concatenate three slices of the array with some additional objects (`r1` and `r2`).
2. **"splice"`**
	* Similar to the "slice" test case, but instead of using the spread operator, it modifies the original array using the `Array.prototype.splice()` method.

**Comparison**

The two test cases compare the performance of using the `Array.prototype.slice()` method versus the `Array.prototype.splice()` method. The comparison is likely aimed at determining which method is faster and more efficient for creating a new array with a subset of elements from an existing array.

**Pros and Cons of Different Approaches:**

* **`slice()`**: This approach is generally considered more efficient because it creates a new array and returns a reference to that array, allowing for further manipulation. However, it can be slower if the original array is very large, since it needs to create a new array with all the elements.
* **`splice()`**: This approach modifies the original array by inserting elements at specific indices. While it may seem counterintuitive to modify an array in this way, it can be more efficient for small arrays because it only updates the affected elements in the original array, rather than creating a new array.

In general, `slice()` is preferred when:

* You need to create a new array with a subset of elements.
* The original array is very large.

On the other hand, `splice()` might be preferred when:

* You need to modify an existing array in place.
* The array is relatively small.

**Library and Special JS Feature**

In this case, there are no libraries or special JavaScript features used. The benchmark focuses on the built-in methods `Array.prototype.slice()` and `Array.prototype.splice()`, which are widely supported by modern browsers.

**Alternative Approaches**

There may be other approaches to creating a new array with a subset of elements, such as:

* Using the `Array.from()` method (available in ECMAScript 2015+): `Array.from(arr).slice(0, 2)`.
* Using the `map()` and `concat()` methods: `[...arr.slice(0, 2), ...arr.slice(2, 5), ...arr.slice(5)]`.
* Using a custom loop or recursive function to create the new array.

These alternatives might be worth considering depending on the specific use case and performance requirements.

Related benchmarks:

splice vs slice (version: 0)

Comparing performance of: slice vs splice

Created: 2 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):