Benchmark: Removal from array

Tests:

Keep items that are not supposed to be removed
let items = [{ id: 1 }, { id: 2 }, { id: 3 }, { id: 4 }, { id: 5 }, { id: 6 }]; const itemsToRemove = [{ id: 2 }, { id: 4 }, { id: 5 }]; items = items.filter(item => !itemsToRemove.find(remove => remove.id === item.id));
Remove items that are supposed to be removed
let items = [{ id: 1 }, { id: 2 }, { id: 3 }, { id: 4 }, { id: 5 }, { id: 6 }]; const itemsToRemove = [{ id: 2 }, { id: 4 }, { id: 5 }]; itemsToRemove.forEach(remove => { const index = items.findIndex(item => item.id === remove.id); items.splice(index, 1); });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Keep items that are not supposed to be removed
Remove items that are supposed to be removed

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**Benchmark Definition:**
The benchmark definition represents a test case where we're removing elements from an array in two different ways:

1. **Using `filter()`**: This approach uses the `filter()` method to create a new array that includes only the items that are not supposed to be removed.
2. **Using `forEach()` and `splice()`**: This approach iterates over the `itemsToRemove` array, finds the index of each item in the original array, and then uses `splice()` to remove the item at that index.

**Options Compared:**
The two approaches compare the performance of using `filter()` versus `forEach()` with `splice()`. The choice of approach can significantly impact performance due to differences in overhead, memory allocation, and iteration mechanisms.

**Pros and Cons:**

* **Using `filter()`**:
	+ Pros: Efficient, concise, and easy to read. It avoids the need for explicit looping and indexing.
	+ Cons: Can be slower for large arrays due to the creation of a new array object.
* **Using `forEach()` with `splice()`**:
	+ Pros: Can be faster for large arrays since it avoids creating a new array object. However, it's more verbose and error-prone.
	+ Cons: Involves modifying the original array, which can lead to unexpected side effects. The use of `splice()` also creates temporary copies of the elements being removed.

**Library Used:**
In this benchmark, there is no explicit library mentioned. However, it's likely that MeasureThat.net handles the underlying JavaScript engine and environment for each browser, ensuring consistent results across different platforms.

**Special JS Feature/Syntax:**
There are no special JavaScript features or syntaxes used in these benchmarks beyond standard JavaScript syntax.

**Other Alternatives:**
For removing elements from an array, some alternative approaches could include:

* Using `map()` with a callback function that returns `undefined` for the items to be removed.
* Using `reduce()` to accumulate the indices of items to be removed and then using `slice()` or `splice()` to remove them.

However, these alternatives might not provide significant performance improvements over the existing approaches, especially considering the trade-offs between readability, conciseness, and performance.

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:75.0) Gecko/20100101 Firefox/75.0

Browser/OS: Firefox 75 on Ubuntu

View result in a separate tab

Test name	Executions per second
Keep items that are not supposed to be removed	2458974.8 Ops/sec
Remove items that are supposed to be removed	1247964.5 Ops/sec

Related benchmarks:

Removal from array (version: 0)

Comparing performance of: Keep items that are not supposed to be removed vs Remove items that are supposed to be removed

Created: 4 years ago by: Guest

Jump to the latest result

Keep items that are not supposed to be removed

Remove items that are supposed to be removed

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):