Benchmark: Includes VS new Set

Tests:

Includes
const arr1 = Array.from({ length: 1_000_000 }, () => Math.floor(Math.random() * 100_000), ) const arr2 = Array.from({ length: 1_000_000 }, () => Math.floor(Math.random() * 100_000), ) const fn = () => { for (const el of arr1) { if (arr2.includes(el)) return true } } fn()
new Set
const arr1 = Array.from({ length: 1_000_000 }, () => Math.floor(Math.random() * 100_000), ) const arr2 = Array.from({ length: 1_000_000 }, () => Math.floor(Math.random() * 100_000), ) const fn = () => { const set = new Set(arr1) for (const el of arr2) { if (set.has(el)) return true } } fn()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Includes
new Set

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.2.1 Safari/605.1.15

Browser/OS: Safari 17 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Includes	4.8 Ops/sec
new Set	4.4 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided benchmark, hosted on MeasureThat.net, compares the performance of two approaches to check if an element exists in an array: using `includes()` and creating a new `Set` from the array.

**What is being tested?**

In this benchmark, we have two test cases:

1. **Includes**: This test case uses the `includes()` method to search for elements in the first array (`arr1`) within the second array (`arr2`). The implementation involves iterating over each element in `arr1` and checking if it exists in `arr2`.
2. **new Set**: In this test case, a new set is created from the elements of `arr1`, and then an element is checked to see if it exists in the set.

**Options compared**

The two options being compared are:

* Using the `includes()` method
* Creating a new `Set` from the array

These two approaches have different performance characteristics, which are the focus of this benchmark.

**Pros and Cons**

### Includes Method

Pros:

* Widely supported and efficient in modern browsers.
* Simple to implement and understand.

Cons:

* May be slower than creating a set for large arrays due to the iteration and lookup process.

### new Set

Pros:

* Can be faster than `includes()` for large arrays because it uses a more optimized data structure (a hash table) for lookups.
* More efficient when dealing with unique elements, as sets only store unique values.

Cons:

* Requires creating an additional object from the array, which can add overhead.
* May require more memory to store the set, depending on the size of the array.

**Library/Technique**

The `includes()` method is a built-in JavaScript function that uses a linear search algorithm. The creation of a new `Set` involves converting the array into an object using the `Array.from()` and `Set()` constructors, which creates a hash table for efficient lookups.

**Special JS Feature/Syntax**

There are no special features or syntaxes used in this benchmark beyond standard JavaScript.

**Other Considerations**

When choosing between these two approaches, consider the specific requirements of your application:

* If you need to check if an element exists in an array frequently, creating a set may be a better choice for performance.
* However, if simplicity and readability are more important than raw speed, using `includes()` might be sufficient.

**Alternatives**

If you're looking for alternative approaches, consider the following:

* Using a library like Lodash's `contains` function, which is optimized for performance and uses a similar approach to creating a set.
* Implementing your own custom lookup data structure, such as a hash table or trie, for optimal performance.

Keep in mind that these alternatives may require more expertise and resources than the built-in `includes()` method.

Related benchmarks:

Includes VS new Set (version: 0)

Comparing performance of: Includes vs new Set

Created: 2 years ago by: Guest

Jump to the latest result

Includes

new Set

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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