Benchmark: spread + splice vs filter to remove one item at given index

Script Preparation code:

var users = [
	{ 'user': 'joey',  'age': 32 },
 	{ 'user': 'ross',    'age': 41 },
  	{ 'user': 'chandler', 'age': 39 },
    	{ 'user': 'chandler', 'age': 39 },
      	{ 'user': 'chandler', 'age': 39 },
    	{ 'user': 'chandler', 'age': 39 },
    	{ 'user': 'chandler', 'age': 39 },
    	{ 'user': 'chandler', 'age': 39 },
    	{ 'user': 'chandler', 'age': 39 },
    	{ 'user': 'chandler', 'age': 39 },

]

Tests:

Filter
const result = users.filter((item, index) => index !== 3);
Slice + spread
let result = [...users]; result.splice(3, 1);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Filter
Slice + spread

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):

LLMs can make mistakes. Check important info.

Measuring the performance of different approaches to remove an item from an array is an interesting benchmark. Let's break down what's being tested and the pros and cons of each approach.

**What's being tested:**

The benchmark compares two approaches:

1. **Filter**: Using the `filter()` method to create a new array with only the items that pass a test (in this case, not being at index 3).
2. **Slice + Spread**: Using the spread operator (`...`) to create a copy of the original array and then removing an item from it using `splice()`, specifically at index 3.

**Pros and Cons:**

**Filter:**

* Pros:
	+ Efficient, as it creates a new array without modifying the original one.
	+ Can be used with arrow functions for a concise implementation.
* Cons:
	+ May not be as readable or intuitive for some developers.
	+ Requires creating a new array, which can be memory-intensive.

**Slice + Spread:**

* Pros:
	+ More readable and straightforward than using `filter()`.
	+ Modifies the original array (which might be desirable in some scenarios).
* Cons:
	+ May not be as efficient as `filter()` since it creates a temporary copy of the array.
	+ Requires creating a new array, which can also lead to memory issues.

**Other considerations:**

Both approaches have similar time complexities (O(n)), so the performance difference might be negligible. However, in real-world scenarios, using `filter()` or spread operator-based approach may depend on specific requirements and personal coding style preferences.

**Library/Features used:**

* No external libraries are used in this benchmark.
* The spread operator (`...`) is a built-in JavaScript feature introduced in ES6 (ECMAScript 2015).

The latest benchmark result shows that both approaches perform similarly, with Chrome 108 achieving around 10 million executions per second for each test. This suggests that the performance difference between these two approaches might be negligible or dependent on other factors like array size and complexity.

**Alternative approaches:**

Other methods to remove an item from an array include:

1. `indexOf()` method and `slice()`: Using `indexOf()` to find the index of the desired element and then using `slice()` to create a new array without that element.
2. `findIndex()` method: Similar to `indexOf()`, but returns the index of the first matching element instead of 0.
3. Custom loop: Writing a custom loop to iterate through the array and remove elements.

Keep in mind that each approach has its pros and cons, and the choice ultimately depends on the specific requirements and coding style preferences.

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/108.0.0.0 Safari/537.36

Browser/OS: Chrome 108 on Windows

View result in a separate tab

Test name	Executions per second
Filter	9673087.0 Ops/sec
Slice + spread	7566637.5 Ops/sec

Related benchmarks:

spread + splice vs filter to remove one item at given index (version: 0)

Remove one item from array and return a new array with filter or slice and spread operator

Comparing performance of: Filter vs Slice + spread

Created: 4 years ago by: Guest

Jump to the latest result

Filter

Slice + spread

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):