Benchmark: unique array items comparison

HTML Preparation code:


<script src='https://cdn.jsdelivr.net/npm/lodash@4.17.10/lodash.min.js'></script>

Tests:

Set()
var l = new Set([1, 2, 3, 4, 5, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7]); return [...l];
lodash uniq
var l = [1, 2, 3, 4, 5, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7]; return _.uniq(l);
native filter
var l = [1, 2, 3, 4, 5, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7]; return l.filter((v, i, self) =>{ return i == self.indexOf(v) })

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Set()
lodash uniq
native filter

Fastest: N/A

Slowest: N/A

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/132.0.0.0 Safari/537.36

Browser/OS: Chrome 132 on Windows

View result in a separate tab

Test name	Executions per second
Set()	7812397.0 Ops/sec
lodash uniq	23622034.0 Ops/sec
native filter	9908993.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what is being tested, compared, and the pros/cons of different approaches.

**Benchmark Overview**

The benchmark tests three ways to compare an array for duplicate elements:

1. Using a native `Set` data structure
2. Using the popular JavaScript library Lodash's `uniq` function
3. Using a native `filter` method with a custom condition

**Tested Approaches**

Each test case represents one of these approaches.

### 1. Native Set Data Structure (`var l = new Set([...])`)

This approach uses a native `Set` data structure to store unique elements from the input array. The `return [...l];` statement converts the `Set` back into an array, which is then returned by the benchmark.

Pros:

* Lightweight and efficient
* Built-in functionality in modern JavaScript engines

Cons:

* May not be as fast as other approaches for very large arrays due to the overhead of creating a `Set`
* Not all browsers support `Set` natively (e.g., older versions of Internet Explorer)

### 2. Lodash `uniq` Function (`var l = [...]; return _.uniq(l);`)

This approach uses Lodash's `uniq` function, which removes duplicate elements from an array.

Pros:

* Fast and efficient, especially for large arrays
* Portable across different browsers and environments, as long as Lodash is included

Cons:

* Requires including Lodash in the project, which can add extra dependencies
* May not be suitable for projects with strict size or weight constraints

### 3. Native `filter` Method (`var l = [...]; return l.filter((v, i, self) =>{ ... });`)

This approach uses a native `filter` method to remove duplicate elements from the array.

Pros:

* Fast and efficient, especially for large arrays
* Built-in functionality in modern JavaScript engines

Cons:

* May not be as readable or maintainable as other approaches due to the complexity of the filtering condition
* Can be slower than Lodash's `uniq` function for very large arrays due to the overhead of creating a filter callback

**Other Considerations**

* The benchmark measures the number of executions per second, which can affect the results. A higher number of executions may indicate better performance.
* The test cases are run in Chrome 118 on Windows Desktop, which may not be representative of other environments or browsers.

**Alternative Approaches**

Some alternative approaches to removing duplicate elements from an array include:

* Using `Array.prototype.reduce()` and an accumulator object to remove duplicates
* Using a library like Ramda's `unique` function (similar to Lodash's `uniq`)
* Implementing a custom algorithm using bitwise operations or other optimization techniques

However, these alternatives may not be as widely supported or efficient as the approaches tested in this benchmark.

Related benchmarks:

unique array items comparison (version: 0)

Comparing performance of: Set() vs lodash uniq vs native filter

Created: 5 years ago by: Guest

Jump to the latest result

Set()

lodash uniq

native filter

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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