Benchmark: filter vs reduce vs difference

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Script Preparation code:

var arrOne = new Array(Math.round(Math.random() * 999) + 1).fill(null).map(elem => Math.round(Math.random() * 998) + 1);
var arrTwo = new Array(Math.round(Math.random() * 999) + 1).fill(null).map(elem => Math.round(Math.random() * 998) + 1);

Tests:

filter() A
var resultA = arrOne.filter(elem => !arrTwo.includes(elem));
filter() B
var resultB = arrOne.filter(elem => !(arrTwo.indexOf(elem) >= 0));
_.filter()
var resultC = _.filter(arrOne, elem => !arrTwo.includes(elem));
_.difference()
var resultD = _.difference(arrOne, arrTwo);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
filter() A
filter() B
_.filter()
_.difference()

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what is being tested, the options compared, their pros and cons, and other considerations.

**Benchmark Purpose**

The benchmark measures the performance of three different approaches to find elements in an array that are not present in another array. The goal is to determine which approach is the fastest for this specific use case.

**Options Compared**

The options compared are:

1. `Array.prototype.filter()`: a native JavaScript method that returns a new array containing all elements that pass the test implemented by the provided function.
2. `_.filter()` from Lodash: a utility function that performs filtering on an array of values to create a new array with only the elements for which a predicate (a condition) is true.
3. `Array.prototype.indexOf()`: a native JavaScript method that returns the index of the first occurrence of a specified value in an array, or -1 if it's not present.

**Pros and Cons**

* **`Array.prototype.filter()`**: Pros:
	+ Native JavaScript implementation, so it's likely to be efficient and have good browser support.
	+ Can be used with any type of data.
	Cons:
	+ Requires iteration over the entire array, which can be slow for large arrays.
* **`_.filter()` from Lodash**: Pros:
	+ Provides a convenient and concise way to perform filtering on arrays.
	+ Includes additional functionality like memoization, which can improve performance in some cases.
Cons:
	+ Adds an extra dependency (Lodash), which may not be desirable for smaller projects.
	+ May have slower execution due to the overhead of the Lodash library.
* **`Array.prototype.indexOf()`**: Pros:
	+ Fast and efficient way to find a single element in an array.
Cons:
	+ Returns -1 if the element is not present, which can lead to unnecessary iterations.

**Other Considerations**

* The benchmark uses dummy data generated using `Math.random()`, which may not be representative of real-world scenarios. More realistic test data might reveal different performance characteristics.
* The `_.difference()` method from Lodash is also included in the benchmark, but it's not clear why this specific method was chosen.

**Library and Syntax**

The Lodash library is used in two of the test cases (`_.filter()` and `_.difference()`). Lodash provides a convenient way to perform common tasks like filtering, mapping, and reducing arrays. The syntax for these methods is often more concise than writing equivalent native JavaScript code.

There are no special JavaScript features or syntaxes used in this benchmark that would require specific knowledge of advanced topics.

**Alternatives**

For this type of benchmark, alternatives might include:

* Other array manipulation libraries like Ramda or Liskel
* In-house implementations using loops and conditional statements
* Native JavaScript methods like `Array.prototype.every()`, `Array.prototype.some()`, or `Set` operations

Keep in mind that the choice of alternative depends on the specific requirements and constraints of the project.

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36

Browser/OS: Chrome 78 on Linux

View result in a separate tab

Test name	Executions per second
filter() A	1780.8 Ops/sec
filter() B	1861.1 Ops/sec
_.filter()	1768.8 Ops/sec
_.difference()	13330.2 Ops/sec

Related benchmarks:

filter vs reduce vs difference (version: 3)

Comparing performance of: filter() A vs filter() B vs _.filter() vs _.difference()

Created: 4 years ago by: Registered User

Jump to the latest result

filter() A

filter() B

_.filter()

_.difference()

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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