Benchmark: filter vs indexOF (test)

Script Preparation code:

var arr = [];
for (var i = 0; i < 1000000; i++) {
  arr.push(Math.floor(Math.random() * 1000));
}
var itemToRemove = arr[Math.floor(Math.random() * 1000000)]

Tests:

indexOf + splice
var result = arr.splice(arr.indexOf(itemToRemove), 1)
filter
var result = arr.filter(el => el !== itemToRemove)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
indexOf + splice
filter

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Linux; Android 10; moto e(7) plus) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.159 Mobile Safari/537.36

Browser/OS: Chrome Mobile 92 on Android

View result in a separate tab

Test name	Executions per second
indexOf + splice	251.4 Ops/sec
filter	2.5 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark and explain what's being tested, compared, and some considerations.

**Benchmark Definition**

The provided JSON represents a JavaScript microbenchmark test case on MeasureThat.net. The test case is designed to compare two approaches:

1. **indexOf + splice**: This approach uses the `indexOf` method to find the index of the item to be removed from the array (`arr`) and then uses the `splice` method to remove that item.
2. **filter**: This approach uses the `filter` method to create a new array with all elements that are not equal to the `itemToRemove`.

**What is being tested?**

The test case measures the performance difference between these two approaches in terms of executions per second.

**Options compared**

The two options are:

1. **indexOf + splice**: This approach involves:
	* Finding the index of the item to be removed using `indexOf`.
	* Removing the item from the array using `splice`.
2. **filter**: This approach involves creating a new array with all elements that are not equal to the `itemToRemove`.

**Pros and Cons**

**indexOf + splice:**

Pros:

* This approach is more explicit and intuitive, as it directly removes the item from the original array.
Cons:

* It requires two separate method calls, which can be slower due to function overhead.

**filter:**

Pros:

* This approach creates a new array with the desired elements, which can be faster since it avoids modifying the original array.
Cons:

* It can create a new array with a larger size than necessary if the filter condition is not met for all elements.

**Other considerations**

* The test case uses an array of 1 million elements, which can impact performance due to memory allocation and garbage collection.
* The `itemToRemove` is randomly selected from the array, which can lead to unpredictable results.
* The test case does not consider edge cases such as empty arrays or duplicate items.

**Library/Extensions**

There are no libraries or extensions explicitly mentioned in the benchmark definition. However, the use of modern JavaScript features like arrow functions (`el => el !== itemToRemove`) and template literals (`var arr = []`) assumes a relatively recent version of JavaScript (ECMAScript 2015+).

**Special JS feature/syntax**

The test case uses the following special JS feature:

* Arrow functions (`el => el !== itemToRemove`): introduced in ECMAScript 2015, these provide a concise way to define small, single-expression functions.
* Template literals (`var arr = []`): introduced in ECMAScript 2015, these allow for more readable string interpolation.

**Alternatives**

Other alternatives to `indexOf + splice` and `filter` could include:

* Using `includes` method instead of `indexOf` (which returns a boolean value)
* Using `map` method with an empty callback function to create a new array without elements
* Using a custom implementation that uses pointer arithmetic or bit manipulation

Keep in mind that the choice of alternative approach depends on the specific requirements and constraints of the use case.

Related benchmarks:

filter vs indexOF (test) (version: 0)

filter vs indexOF

Comparing performance of: indexOf + splice vs filter

Created: 3 years ago by: Guest

Jump to the latest result

indexOf + splice

filter

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):