Benchmark: set vs array - MeasureThat.net

Script Preparation code:

var a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
var b = new Set(a)

Tests:

array
a.includes(10)
set
b.has(10)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
array
set

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
array	82069936.0 Ops/sec
set	143665728.0 Ops/sec

Autogenerated LLM Summary (model gemma2:9b, generated one year ago):

LLMs can make mistakes. Check important info.

This benchmark compares the performance of checking for the existence of an element in an array versus a Set using `includes` and `has` methods respectively.

**Options Compared:**

* **Array (`a.includes(10)`)**: Uses the `includes` method to check if the value `10` exists within the array `a`.
* **Set (`b.has(10)`)**:  Uses the `has` method to check if the value `10` exists within the Set `b`.

**Pros and Cons:**

* **Array (includes):**
    * **Pro:**  Arrays are a more common data structure in JavaScript, so developers may be more familiar with using them. 
    * **Con:** `includes` performs a linear search through the array, which can be slow for large arrays.
* **Set (has):**
    * **Pro:** Sets utilize hash tables internally, enabling near-constant time complexity (O(1)) for checking element existence. This makes them significantly faster than arrays for this operation, especially with larger datasets.
    * **Con:** Sets have a more limited set of operations compared to arrays (e.g., they don't support indexing by position).

**Other Considerations:**

* **Use Case:** If you need fast membership checking and uniqueness is important, use a Set.  If you require ordered data or specific array manipulation methods, an array might be more suitable.
* **Dataset Size:** For small datasets, the performance difference between arrays and sets may be negligible. However, as the dataset size grows, the advantage of using a set becomes more pronounced.

**Alternatives:**

* **Using a Map:**  Maps are key-value pairs similar to objects but offer faster lookups than standard JavaScript objects. If you need both membership checking and associated data values, Maps could be a good alternative.

Let me know if you have any other questions!

Related benchmarks:

set vs array (version: 0)

Comparing performance of: array vs set

Created: 5 years ago by: Guest

Jump to the latest result

array

set

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gemma2:9b, generated one year ago):