Benchmark: Remove duplicates from array of objects

Script Preparation code:

var array = [];
for (let i = 0; i < 100000; i++) {
   array.push({value: Math.floor((Math.random() * 10) + 1)});
}

Tests:

Using indexOf
array.filter((item, index) => array.indexOf(item) != index);
Using lastIndexOf
array.filter((item, index) => array.lastIndexOf(item) != index);
Using a Set
[...new Set(array)]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Using indexOf
Using lastIndexOf
Using a Set

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):

LLMs can make mistakes. Check important info.

I'd be happy to explain what's being tested in this benchmark.

**Benchmark Purpose**

The goal of this benchmark is to measure the performance of three different approaches for removing duplicates from an array of objects in JavaScript:

1. Using `indexOf` method
2. Using `lastIndexOf` method
3. Using a `Set` data structure

**Approach 1: Using `indexOf` method**

This approach uses the `indexOf` method to check if an element exists in the array. If the index of the element is not equal to its own value, it means the element already exists in the array and can be removed.

Pros:

* Simple and straightforward implementation
* Easy to understand and maintain

Cons:

* This approach has a high overhead due to the repeated use of `indexOf` method for each iteration. It's also vulnerable to performance degradation if the array is large, since it needs to search through the entire array to find the element.
* Not recommended for large datasets.

**Approach 2: Using `lastIndexOf` method**

This approach uses the `lastIndexOf` method to check if an element exists in the array. If the last index of the element is not equal to its own value, it means the element already exists in the array and can be removed.

Pros:

* Similar to using `indexOf`, but potentially faster since it searches from the end of the array
* Easy to understand and maintain

Cons:

* This approach also has a high overhead due to repeated use of `lastIndexOf` method. It's not significantly faster than using `indexOf`.
* Still vulnerable to performance degradation for large datasets.

**Approach 3: Using a `Set` data structure**

This approach uses the `Set` data structure to store unique elements from the array. This way, only one instance of each element is stored in the set, making it efficient for removing duplicates.

Pros:

* Highly efficient and scalable
* Fast and reliable

Cons:

* Requires extra memory for storing the set
* Can be complex to understand and implement, especially for developers without experience with data structures.

**Library: `Set`**

The `Set` object is a built-in JavaScript data structure that stores unique elements. It's implemented as a hash table, which allows it to efficiently look up and store elements.

**Special JS feature/Syntax**

None mentioned in this benchmark.

**Other Alternatives**

Other alternatives for removing duplicates from an array of objects include:

* Using `Map` instead of `Set`, since it preserves the order of elements
* Using a custom implementation using arrays, loops, and conditional statements
* Using a library like Lodash or Underscore.js that provides built-in functions for set operations

It's worth noting that these alternatives may have their own trade-offs in terms of performance, memory usage, and complexity.

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/119.0

Browser/OS: Firefox 119 on Linux

View result in a separate tab

Test name	Executions per second
Using indexOf	2.6 Ops/sec
Using lastIndexOf	0.8 Ops/sec
Using a Set	87.7 Ops/sec

Related benchmarks:

Remove duplicates from array of objects (version: 0)

Comparing performance of: Using indexOf vs Using lastIndexOf vs Using a Set

Created: one year ago by: Guest

Jump to the latest result

Using indexOf

Using lastIndexOf

Using a Set

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):