Benchmark: slice + spread vs filter vs spread copy + splice 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
const result = [...users.slice(0, 3), ...users.slice(4)];
spread copy + splice
const result = [...users].splice(3, 1);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Filter
Slice + spread
spread copy + splice

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/93.0.4577.82 Safari/537.36

Browser/OS: Chrome 93 on Windows

View result in a separate tab

Test name	Executions per second
Filter	7287477.0 Ops/sec
Slice + spread	2745481.0 Ops/sec
spread copy + splice	5446556.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Measuring the performance of different approaches to remove an item from an array in JavaScript can be done using various methods, each with its pros and cons.

**Approaches Compared**

1. **Filter**: The `filter()` method creates a new array with all elements that pass the test implemented by the provided function.
2. **Slice + Spread**: This approach uses the `slice()` method to extract a slice of the array and then spreads it into a new array using the spread operator (`...`).
3. **Spread Copy + Splice**: This approach creates a copy of the original array using the spread operator, modifies the copied array by removing an item with `splice()`, and returns the modified copy.

**Pros and Cons**

1. **Filter**
	* Pros:
		+ Easy to read and understand.
		+ Does not modify the original array.
	* Cons:
		+ Creates a new array, which can be memory-intensive for large datasets.
		+ May have performance implications due to function call overhead.
2. **Slice + Spread**
	* Pros:
		+ Efficient in terms of memory usage since it creates a new array that references the original elements.
		+ Fast execution time since it avoids creating a new array with multiple elements.
	* Cons:
		+ Creates an intermediate slice, which can lead to increased memory usage for very large datasets.
		+ May have performance implications due to function call overhead and string concatenation.
3. **Spread Copy + Splice**
	* Pros:
		+ Efficient in terms of memory usage since it creates a copy of the original array without modifying it.
		+ Fast execution time since it uses `splice()` to remove an element from the copied array.
	* Cons:
		+ Creates an intermediate copy, which can lead to increased memory usage for very large datasets.
		+ May have performance implications due to function call overhead and string concatenation.

**Library and Special JS Features**

The benchmark script does not use any external libraries. However, it uses a special JavaScript feature: the spread operator (`...`). The spread operator is a relatively new feature introduced in ECMAScript 2015 (ES6) that allows for creating new arrays from iterables or other spreads.

**Other Alternatives**

1. **Array.prototype.map()**: This method creates a new array with the results of applying a provided function on every element in this array.
2. **Array.prototype.reduce()**: This method reduces an array to a single value, which can be used as a replacement for the removed item.
3. **Set or Map data structures**: These data structures provide efficient methods for removing elements, but may require additional setup and memory allocation.

It's essential to consider the specific requirements of your use case when choosing an approach. For example, if you need to remove an element from a large dataset, the spread copy + splice approach might be more suitable due to its efficiency in terms of memory usage. However, if readability and maintainability are crucial, the filter approach might be a better choice.

Related benchmarks:

slice + spread vs filter vs spread copy + splice 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 vs spread copy + splice

Created: 3 years ago by: Guest

Jump to the latest result

Filter

Slice + spread

spread copy + splice

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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