Benchmark: Unique Array - MeasureThat.net

Script Preparation code:

var arr = ['1', '2', '2', '3', '4', '5', '6'];

Tests:

Set
Array.from(new Set(arr))
for loop
const set = []; for (const i of arr) { if (set.indexOf(i) === -1) set.push(i) }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Set
for loop

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.2 Safari/605.1.15

Browser/OS: Safari 15 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Set	2682025.5 Ops/sec
for loop	7117794.5 Ops/sec

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

LLMs can make mistakes. Check important info.

**Overview of the Benchmark**

The provided benchmark, hosted on MeasureThat.net, tests two approaches to creating a unique array from a duplicate array: using the `Array.from(new Set())` method and a simple for loop.

**Approach 1: Using `Array.from(new Set())`**

This approach creates an instance of `Set`, which automatically removes duplicates from the input array. The `Array.from()` method is then used to convert the set back into an array.

**Pros:**

* Efficient, as sets are optimized for fast lookup and insertion operations.
* Simple to implement in code.
* No need to manually iterate through the array or use conditional statements.

**Cons:**

* May not perform well with large arrays due to the overhead of creating a set.
* Requires modern JavaScript versions (ECMAScript 2015+).

**Approach 2: Using a for loop**

This approach manually iterates through the input array, checks if each element is already present in the resulting array using `indexOf()`, and adds it if not.

**Pros:**

* Can be more efficient with large arrays, as it avoids creating an intermediate set.
* Works with older JavaScript versions (pre-ECMAScript 2015).
* No additional libraries or dependencies are required.

**Cons:**

* More complex to implement in code due to the need for manual iteration and conditional statements.
* May have performance issues if the loop iterates slowly or if the `indexOf()` method is slow.

**Library Used:**

The `Set` object is a built-in JavaScript library, which is available since ECMAScript 2015. It's used in the first approach to remove duplicates from the array.

**Special JS Feature/Syntax:**

None of the approaches rely on special JavaScript features or syntax beyond what's mentioned above (ECMAScript 2015+).

**Other Alternatives:**

If you prefer a more concise approach, you could use `Array.from()` with an arrow function to achieve the same result:
```javascript
const uniqueArr = Array.from(arr, i => arr.indexOf(i) === -1 ? i : null).filter(Boolean);
```
Keep in mind that this approach still uses modern JavaScript features and may not be suitable for older versions.

If you want to use a library or utility function to remove duplicates, you could consider using `lodash` (a popular utility library) or a custom implementation.

Related benchmarks:

Unique Array (version: 0)

Comparing performance of: Set vs for loop

Created: 2 years ago by: Guest

Jump to the latest result

Set

for loop

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):