Benchmark: set.has vs. array.includes 1e5

Script Preparation code:

var a = new Array(1e5);
var lastIndex = a.length - 1;
for(i=0, I = a.length; i < I; i++) {
  a[i] = i;
}

var b = new Set(a);

Tests:

includes
return a.includes(lastIndex)
has
return b.has(lastIndex)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
includes
has

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/537.36 (KHTML, like Gecko) Chrome/97.0.4692.71 Safari/537.36

Browser/OS: Chrome 97 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
includes	9883.5 Ops/sec
has	7428904.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in the provided JSON benchmark.

The benchmark is comparing two approaches for checking if an element exists in a data structure: `set.has()` and `array.includes()`. The test case uses two arrays of size 1e5 (100,000 elements) with values from 0 to 99,999. The array `a` is prepared by setting each element to its index value.

**Approaches being compared:**

1. **`set.has()`**: This method is part of the JavaScript `Set` object, which automatically removes duplicates and provides fast membership testing.
2. **`array.includes()`**: This method is used for searching an element within a given array. It iterates through the array to find the specified value.

**Pros and Cons:**

* **`set.has()`**:
	+ Pros: Fast (O(1) average time complexity), efficient, and accurate.
	+ Cons: Requires a `Set` object, which may not be suitable for all use cases. Also, this method only works on JavaScript engines that support `Set`.
* **`array.includes()`**:
	+ Pros: Simple to implement, widely supported by most browsers and environments.
	+ Cons: Iterates through the entire array (O(n) time complexity), which can lead to slower performance for large datasets.

The test users special JS feature or syntax: None mentioned.

**Other considerations:**

* The benchmark uses a very large dataset (1e5 elements) to emphasize the performance difference between these two approaches.
* The use of `Set` for this specific task may not be necessary, as the array already contains unique values. However, using `Set` can provide a more efficient solution if you need to perform membership testing on a set of elements.

**Alternatives:**

For smaller datasets, you might want to consider using other methods like:

* Using a `Map` or an object for fast lookup.
* Utilizing the `in` operator with arrays or sets.

However, for large datasets like in this benchmark, `set.has()` will likely outperform `array.includes()` due to its O(1) time complexity.

Related benchmarks:

set.has vs. array.includes 1e5 (version: 0)

Comparing performance of: includes vs has

Created: 2 years ago by: Guest

Jump to the latest result

includes

has

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):