Benchmark: uniqBy vs filter+set

HTML Preparation code:

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

Script Preparation code:

var smalldata = [1,2,3,4,5,'ok','abc','def',null,undefined,1,2,3,'ok'];
var bigdata = [1,2,3,4,5,'ok','abc','def',null,undefined,1,2,3,'ok',1,2,3,4,5,'ok','abc','def',null,undefined,1,2,3,'ok',1,2,3,4,5,'ok','abc','def',null,undefined,1,2,3,'ok',1,2,3,4,5,'ok','abc','def',null,undefined,1,2,3,'ok',1,2,3,4,5,'ok','abc','def',null,undefined,1,2,3,'ok',1,2,3,4,5,'ok','abc','def',null,undefined,1,2,3,'ok',1,2,3,4,5,'ok','abc','def',null,undefined,1,2,3,'ok',1,2,3,4,5,'ok','abc','def',null,undefined,1,2,3,'ok',1,2,3,4,5,'ok','abc','def',null,undefined,1,2,3,'ok'];

var uniqBy = (arr, fn) => {
  var dups = new Set();
  return arr.filter((v) => {
    const k = fn(v);
    if (dups.has(k)) {
      return false;
    }
    dups.add(k);
    return true;
  });
};

Tests:

lodash/uniqBy
_.uniqBy(smalldata, (v) => v); _.uniqBy(bigdata, (v) => v);
filter+set
uniqBy(smalldata, (v) => v); uniqBy(bigdata, (v) => v);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
lodash/uniqBy
filter+set

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Linux

View result in a separate tab

Test name	Executions per second
lodash/uniqBy	190904.4 Ops/sec
filter+set	352976.2 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the provided JSON and explain what's being tested, compared, and the pros and cons of each approach.

**Benchmark Definition**

The benchmark is comparing two approaches to remove duplicates from an array: `uniqBy` (using Lodash) and `filter+set`.

**What is being tested?**

The test cases are running the following code:

1. Using Lodash's `uniqBy` function:
```javascript
_.uniqBy(smalldata, (v) => v);
_.uniqBy(bigdata, (v) => v);
```
2. A custom implementation using `filter+set`:
```javascript
uniqBy(smalldata, (v) => v);
uniqBy(bigdata, (v) => v);
```
The test cases are comparing the execution times of both approaches on two datasets: `smalldata` and `bigdata`.

**What options are being compared?**

* `uniqBy` (using Lodash): This function uses a Set to keep track of unique values. It iterates through the array, applies the provided function to each value, and returns an array with only the unique values.
* `filter+set`: This approach involves creating a Set to store unique values and filtering the original array using the same set.

**Pros and Cons**

* `uniqBy` (using Lodash):
	+ Pros:
		- More concise and readable code
		- Lodash provides a stable way to handle duplicate removal
	+ Cons:
		- Requires an external library (Lodash)
		- May have additional overhead due to the library's execution
* `filter+set`:
	+ Pros:
		- No additional dependencies or libraries required
		- Can be more efficient for large datasets, as it avoids creating a new array with unique values
	+ Cons:
		- Code can be longer and less readable
		- Requires manual management of the Set data structure

**Library: Lodash**

Lodash is a popular JavaScript utility library that provides a wide range of functions for common tasks, including string manipulation, array manipulation, and more. The `uniqBy` function in particular is designed to remove duplicates from an array based on a provided function.

**Special JS feature or syntax: None mentioned**

There are no special features or syntax used in this benchmark.

**Other alternatives**

* For removing duplicates without using Lodash, you can use the following approaches:
	+ Using `Map` and `Array.from`: Create a Map with unique values and then convert it back to an array.
	+ Using `Set` and `Array.prototype.filter()`: Similar to the `filter+set` approach, but uses `Set` to store unique values and filters the original array.
* For removing duplicates while preserving the original order, you can use a different approach, such as using an object with unique keys.

I hope this explanation helps!

Related benchmarks:

uniqBy vs filter+set (version: 0)

Comparing performance of: lodash/uniqBy vs filter+set

Created: 4 years ago by: Registered User

Jump to the latest result

lodash/uniqBy

filter+set

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):