Benchmark: Lodash uniq vs Set transformation

HTML Preparation code:

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

Tests:

Array from set
const values = ['testing', 'test', 'foo', 'bar', 'test', 'test', 'test', 'testing', 'foo', 'bar', 'meow', 'hi', 'test', 'nothing', 'something']; Array.from(new Set(values))
uniq
const values = ['testing', 'test', 'foo', 'bar', 'test', 'test', 'test', 'testing', 'foo', 'bar', 'meow', 'hi', 'test', 'nothing', 'something']; _.uniq(values)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array from set
uniq

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.182 Safari/537.36

Browser/OS: Chrome 88 on Linux

View result in a separate tab

Test name	Executions per second
Array from set	864980.9 Ops/sec
uniq	2769641.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks.

**What is being tested?**

MeasureThat.net provides a JSON representation of a benchmark, which includes two test cases: `Array from set` and `uniq`. The first test case uses the built-in `Set` data structure in JavaScript to transform an array of values into a new array with unique elements. The second test case uses the popular utility library Lodash's `uniq` function to achieve the same result.

**Options being compared**

In this benchmark, two approaches are being compared:

1. **Built-in `Set`**: This approach uses the built-in `Set` data structure in JavaScript to transform an array of values into a new array with unique elements. The advantage of this approach is that it's a native implementation and likely to be fast.
2. **Lodash's `uniq` function**: This approach uses Lodash's `uniq` function, which is a utility function that removes duplicate elements from an array. The advantage of this approach is that it's a well-tested and optimized library function.

**Pros and Cons**

Here are some pros and cons for each approach:

1. **Built-in `Set`**:
	* Pros: Fast, native implementation.
	* Cons: May not work as expected if the input array contains non-unique elements (e.g., strings that have different representations in JavaScript), and may not be compatible with older browsers or environments.
2. **Lodash's `uniq` function**:
	* Pros: Well-tested, optimized library function; works with any type of data.
	* Cons: Requires an additional dependency (the Lodash library).

**Library usage**

In this benchmark, the Lodash library is used for the second test case (`uniq`). The library provides a convenient and efficient way to remove duplicate elements from an array.

**Special JS feature or syntax**

There are no special JavaScript features or syntax used in these test cases. However, it's worth noting that some modern browsers may optimize certain operations using WebAssembly or other techniques, which could affect the benchmark results.

**Other alternatives**

If you were to implement a custom `uniq` function without using an existing library like Lodash, here are some alternative approaches:

1. **Using a `Map`**: Create a map with the elements as keys and the values as arrays. Then, iterate over the original array and for each element, check if it exists in the map. If it does, remove it from the map.
2. **Using a regular expression**: Use a regular expression to match duplicate elements and replace them with unique ones.

Here's an example of how you might implement a custom `uniq` function using a `Map`:
```javascript
function uniq(arr) {
  const map = new Map();
  return arr.filter((x) => {
    if (map.has(x)) {
      return false;
    }
    map.set(x, true);
    return true;
  });
}
```
Keep in mind that this implementation has the same pros and cons as the built-in `Set` approach.

Related benchmarks:

Lodash uniq vs Set transformation (version: 0)

Comparing performance of: Array from set vs uniq

Created: 3 years ago by: Guest

Jump to the latest result

Array from set

uniq

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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