Benchmark: Filter vs toSpliced

Script Preparation code:

var arr = ['a', 'b', 'c', 'd', 'e', 'f', 'g'];
var indexToRemove = 3;

Tests:

Filter
arr.filter((item, index) => index !== indexToRemove)
toSpliced
arr.toSpliced(indexToRemove, 1)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Filter
toSpliced

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36 Edg/124.0.0.0

Browser/OS: Chrome 124 on Windows

View result in a separate tab

Test name	Executions per second
Filter	2790777.2 Ops/sec
toSpliced	6613441.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and analyze what's being tested.

**What is being tested?**

The provided JSON represents a JavaScript microbenchmark test case. It contains two individual test cases: "Filter" and "toSpliced". These test cases measure the performance of two different approaches to remove an element from an array.

**Options compared**

In this benchmark, we have two options:

1. **`arr.filter((item, index) => index !== indexToRemove)`**: This option uses the `filter()` method with a callback function to create a new array that excludes elements at the specified index.
2. **`arr.toSpliced(indexToRemove, 1)`**: This option uses the `toSpliced()` method (not a built-in JavaScript method, but rather an example of how to remove an element from an array using indexing) to replace the element at the specified index with a new value.

**Pros and Cons**

Both approaches have their advantages and disadvantages:

* **`arr.filter((item, index) => index !== indexToRemove)`**:
	+ Pros: concise and readable code, doesn't modify the original array.
	+ Cons: can be slower due to the creation of a new array.
* **`arr.toSpliced(indexToRemove, 1)`**:
	+ Pros: modifies the original array, potentially faster than `filter()` because it avoids creating a new array.
	+ Cons: less readable code, may modify the original array unexpectedly.

In general, if you need to remove an element from an array and don't care about modifying the original array, `arr.filter((item, index) => index !== indexToRemove)` might be a better choice. However, if you're working with large datasets or need to optimize for performance, `arr.toSpliced(indexToRemove, 1)` could be a better option.

**Library and purpose**

In this benchmark, there is no explicit library being used. The `toSpliced()` method is likely an example implementation provided by the test author, demonstrating how to remove an element from an array using indexing.

**Special JS feature or syntax**

There is no special JavaScript feature or syntax being tested in this benchmark. Both approaches are standard JavaScript methods and can be implemented in any modern JavaScript environment.

**Other alternatives**

In general, when removing an element from an array, you might also consider using:

* `splice()`: Similar to `toSpliced()`, but uses the `splice()` method instead of indexing.
* `at()` or `itemAt()`: Some browsers support these methods for accessing elements at specific indices in arrays.

However, it's worth noting that these alternatives may have different performance characteristics and trade-offs compared to the two options being tested here.

I hope this explanation helps!

Related benchmarks:

Filter vs toSpliced (version: 0)

Comparing performance of: Filter vs toSpliced

Created: one year ago by: Guest

Jump to the latest result

Filter

toSpliced

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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