Benchmark: lodash uniq vs [...new Set]

HTML Preparation code:

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

Tests:

Set
var l = [...new Set([1, 2, 3, 4, 5, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7])]; return l;
Array
var l = [1, 2, 3, 4, 5, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7]; return _.uniq(l);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Set
Array

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 19 hours ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:140.0) Gecko/20100101 Firefox/140.0

Browser/OS: Firefox 140 on Windows

View result in a separate tab

Test name	Executions per second
Set	3648056.5 Ops/sec
Array	8912620.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark compares two approaches to remove duplicates from an array: using a `Set` object and using Lodash's `uniq()` function.

**Options Compared**

There are two options being compared:

1. **Using a Set Object**: This approach uses the built-in `Set` object in JavaScript, which automatically removes duplicates by only storing unique values.
2. **Using Lodash's uniq() Function**: This approach uses the `uniq()` function from the Lodash library, which also removes duplicates from an array.

**Pros and Cons**

**Using a Set Object:**

Pros:

* Fast and efficient, as it leverages the optimized implementation of the `Set` object.
* Simple to implement and understand.
* Eliminates duplicates in a single pass through the data.

Cons:

* May not work as expected if the input array contains non-numeric or non-string values that can be hashed (e.g., objects, functions).
* Does not preserve the original order of elements.

**Using Lodash's uniq() Function:**

Pros:

* Preserves the original order of elements.
* Works with any type of data that can be compared using the `===` operator.
* Can handle edge cases like NaN and undefined values.

Cons:

* Slower than using a `Set` object, as it iterates over the array and checks for duplicates using the `===` operator.
* Requires an external library (Lodash), which may add overhead and dependencies.

**Library: Lodash**

Lodash is a popular JavaScript utility library that provides a collection of functional programming helpers. In this benchmark, the `uniq()` function is used to remove duplicates from an array. The `uniq()` function takes an optional second argument to specify the comparison function; in this case, no comparison function is provided, so it defaults to the default comparison function.

**Special JS Feature or Syntax**

There are no special JavaScript features or syntaxes being tested in this benchmark. However, it's worth noting that the use of Lodash and the `Set` object both rely on modern JavaScript features like closures and prototypal inheritance.

**Other Alternatives**

If you didn't have access to Lodash, you could implement a custom implementation for removing duplicates from an array using the following approach:

```javascript
function removeDuplicates(arr) {
  const seen = {};
  return arr.filter(x => seen[x] === undefined ? seen[x] = true : false);
}
```

This implementation uses a simple object (`seen`) to keep track of unique values and iterates over the input array using the `filter()` method.

Alternatively, you could use a more advanced algorithm like the "counting sort" or "bucket sort" approach, which can be more efficient for large datasets but are also more complex to implement.

Related benchmarks:

lodash uniq vs [...new Set] (version: 0)

Comparing performance of: Set vs Array

Created: 4 years ago by: Guest

Jump to the latest result

Set

Array

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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