Benchmark: Unique values - MeasureThat.net

Script Preparation code:

var array = [ 1, 2, 2, 1, 3];

Tests:

Set
[...new Set(array)];
Filter
array.filter((item, index) => array.indexOf(item) === index);
Reduce
array.reduce((unique, item) => unique.includes(item) ? unique : [...unique, item], []);
Lodash
_.uniq(array)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Set
Filter
Reduce
Lodash

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The provided benchmark compares the performance of four different approaches for removing duplicates from an array: `Set`, `Filter`, `Reduce`, and `Lodash's uniq` function.

**Script Preparation Code**

The script preparation code defines the input array:
```javascript
var array = [1, 2, 2, 1, 3];
```
This array has duplicate values to simulate a scenario where duplicates need to be removed.

**Html Preparation Code**

Since there is no HTML preparation code provided, we can assume that it's not required for this benchmark or is already handled by the MeasureThat.net framework.

**Individual Test Cases**

Each test case has a `Benchmark Definition` property that defines how to create an array with unique values. There are four test cases:

1. **Set**: `[...new Set(array)]`
This approach creates a new `Set` object from the input array, which automatically removes duplicates.
2. **Filter**: `array.filter((item, index) => array.indexOf(item) === index)`
This approach uses the `filter()` method to create a new array with only unique elements. The callback function checks if each element is already present at its original index in the array.
3. **Reduce**: `array.reduce((unique, item) => unique.includes(item) ? unique : [...unique, item], [])`
This approach uses the `reduce()` method to iterate over the input array and create a new array with unique elements. The accumulator variable `unique` is initialized as an empty array, and for each element, it checks if the element is already present in the accumulator using the `includes()` method.
4. **Lodash's uniq**: `_.uniq(array)`
This approach uses Lodash's `uniq()` function to remove duplicate values from the input array.

**Pros and Cons of Each Approach**

1. **Set**:
	* Pros: Fast, efficient, and concise.
	* Cons: Requires a modern JavaScript environment that supports Set objects (introduced in ECMAScript 2015).
2. **Filter**:
	* Pros: Simple, easy to understand, and works with older browsers.
	* Cons: Less efficient than the other approaches, as it creates a new array with filtered elements.
3. **Reduce**:
	* Pros: Flexible, can be used for more complex data processing tasks.
	* Cons: Less efficient than the Set approach, as it uses an accumulator variable and checks for duplicates using `includes()`.
4. **Lodash's uniq**:
	* Pros: Convenient, easy to use, and works with older browsers that support Lodash.
	* Cons: Requires a dependency on Lodash, which adds overhead.

**Other Alternatives**

1. **Array.prototype.reduceRight()**: Similar to the `reduce()` method, but iterates over the array in reverse order.
2. **Array.prototype.filter()`: Removes elements from an array that do not meet a specified condition (similar to the Filter approach).
3. **Array.prototype.map()`: Creates a new array with transformed values, which can be used in combination with `filter()` or other methods.

In conclusion, each approach has its strengths and weaknesses, and the choice of method depends on the specific use case, performance requirements, and personal preference.

Latest run results:

Run details: (Test run date: 8 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36

Browser/OS: Chrome 122 on Windows

View result in a separate tab

Test name	Executions per second
Set	9009732.0 Ops/sec
Filter	5748371.0 Ops/sec
Reduce	13698824.0 Ops/sec
Lodash	11298925.0 Ops/sec

Related benchmarks:

Unique values (version: 0)

Comparing performance of: Set vs Filter vs Reduce vs Lodash

Created: 4 years ago by: Guest

Jump to the latest result

Set

Filter

Reduce

Lodash

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):