Benchmark: Splice vs new Array

Script Preparation code:

var randomArray=Array.from({length: 1000}, () => Math.floor(Math.random() * 100));

Tests:

Splice
for (let i = randomArray.length - 1; i >= 0; --i) { if (randomArray[i] !== 1) { continue; } randomArray.splice(i, 1); } return randomArray;
Copy to new
const newArray = []; for (let i = randomArray.length - 1; i >= 0; --i) { if (randomArray[i] !== 1) { continue; } newArray.push(randomArray[i]); } return newArray;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Splice
Copy to new

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 dive into the world of JavaScript microbenchmarks!

**What is being tested?**

The provided JSON represents two individual test cases, each testing different approaches to remove elements from an array in JavaScript. The first test case, "Splice", tests using the `splice()` method to remove elements from the original array, while the second test case, "Copy to new", creates a new array by copying elements from the original array.

**Options being compared:**

The two options being compared are:

1. **Splice**: Removing elements from the original array using the `splice()` method.
2. **Copy to new**: Creating a new array by copying elements from the original array using the `Array.from()` and `push()` methods.

**Pros and cons of each approach:**

**Splice:**

Pros:

* Efficient for large arrays, as it only modifies the original array.
* Can be faster in some cases, especially when dealing with very large arrays.

Cons:

* Modifies the original array, which can have unintended side effects if not properly handled.
* May cause issues if the array is modified concurrently by other parts of the codebase.

**Copy to new:**

Pros:

* Does not modify the original array, preserving its integrity.
* Can be safer and more predictable when dealing with concurrent modifications or when preserving the original data.

Cons:

* Creates a new array, which can consume more memory for large datasets.
* May be slower than `splice()` due to the overhead of creating a new array and iterating over the elements.

**Library and purpose:**

In this benchmark, there is no external library being used. The JavaScript standard library provides the necessary functions (`Array.from()`, `push()`, and `splice()`).

**Special JS feature or syntax:**

There are no special features or syntaxes being tested in this benchmark. The tests focus on comparing two common approaches to array manipulation.

**Other alternatives:**

If you're interested in exploring other approaches, here are a few options:

* **Array.prototype.slice()**: Creates a shallow copy of the original array using slicing.
* **map() + filter()**: Creates a new array by mapping over the original array and filtering out elements that meet certain conditions.
* **set() + delete**: Uses a Set to remove duplicates from an array, which can be more efficient than `splice()` for large datasets.

Keep in mind that each alternative has its pros and cons, and the best approach depends on the specific use case and performance requirements.

Related benchmarks:

Splice vs new Array (version: 0)

Comparing performance of: Splice vs Copy to new

Created: 3 years ago by: Guest

Jump to the latest result

Splice

Copy to new

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):