Benchmark: _.uniqWith(arr, _.isEqual).length vs new Set(arr).size 1

HTML Preparation code:

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

Script Preparation code:

var arr = Array.from({length: 40}, () => Math.floor(Math.random() * 40));

var newArr = null;

Tests:

_.uniqWith(arr, _.isEqual).length
newArr = _.uniqWith(arr, _.isEqual)
new Set(arr).size
newArr = new Set(arr)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
_.uniqWith(arr, _.isEqual).length
new Set(arr).size

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks and explore what's tested in the provided JSON.

**Benchmark Definition**

The benchmark is designed to compare two approaches for finding unique elements in an array:

1. Using `_.uniqWith(arr, _.isEqual)` from the Lodash library.
2. Using a built-in JavaScript method `new Set(arr).size`.

**Options Compared**

These two options are compared because they have different performance characteristics.

* `_.uniqWith(arr, _.isEqual)`: This approach uses the Lodash library's `uniqWith` function, which takes a callback function as an argument. In this case, the callback is set to `_.isEqual`, which checks for equality using the `===` operator. This approach is likely to be slower because it involves an additional function call and potentially more memory allocations.
* `new Set(arr).size`: This approach uses the built-in JavaScript method `Set`. A `Set` object in JavaScript is a collection of unique values, and its `size` property returns the number of elements in the set. This approach is likely to be faster because it's a native JavaScript method that doesn't involve any additional function calls or memory allocations.

**Pros and Cons**

Here are some pros and cons of each approach:

* `_.uniqWith(arr, _.isEqual)`:
	+ Pros: Easy to implement, readable code.
	+ Cons: Slower performance due to additional function call and potential memory allocations.
* `new Set(arr).size`:
	+ Pros: Faster performance, more memory-efficient.
	+ Cons: Requires understanding of the built-in JavaScript method `Set`, potentially harder to implement.

**Lodash Library**

The Lodash library is a popular utility library for JavaScript that provides a wide range of functions for tasks like array manipulation, string processing, and more. In this case, the `uniqWith` function is used to find unique elements in an array while preserving the original order.

**Special JS Feature/Syntax (None)**

There are no special JavaScript features or syntaxes being tested in this benchmark.

**Other Alternatives**

If you're looking for alternative approaches to finding unique elements in an array, here are a few options:

* Using `Array.prototype.filter()` and `Array.prototype.indexOf()`: This approach involves filtering the array to find unique elements using `filter()` and then iterating over the resulting array to count the number of unique elements using `indexOf()`.
* Using `Array.prototype.reduce()` and `Set`: This approach involves reducing the array to a set of unique values using `reduce()` and then counting the size of the resulting set.
* Using `Array.prototype.forEach()` and `Set`: This approach involves iterating over the array using `forEach()` and adding each element to a set, which automatically eliminates duplicates.

Here's some sample code for these alternative approaches:
```javascript
// Using Array.prototype.filter() and Array.prototype.indexOf()
const uniqueElements = arr.filter((element) => {
  return arr.indexOf(element) === -1;
}).length;

// Using Array.prototype.reduce() and Set
const uniqueElements = arr.reduce((set, element) => {
  set.add(element);
  return set.size;
}, new Set()).size;

// Using Array.prototype.forEach() and Set
arr.forEach((element) => {
  const set = new Set();
  set.add(element);
  // ...
});
```
Note that these alternative approaches may have different performance characteristics than the original benchmark.

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/110.0.0.0 Safari/537.36 Edg/110.0.1587.56

Browser/OS: Chrome 110 on Windows

View result in a separate tab

Test name	Executions per second
_.uniqWith(arr, _.isEqual).length	1362417.5 Ops/sec
new Set(arr).size	1230021.5 Ops/sec

Related benchmarks:

_.uniqWith(arr, _.isEqual).length vs new Set(arr).size 1 (version: 3)

Comparing performance of: _.uniqWith(arr, _.isEqual).length vs new Set(arr).size

Created: one year ago by: Registered User

Jump to the latest result

_.uniqWith(arr, _.isEqual).length

new Set(arr).size

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):