Benchmark: set.has vs. array.includes for single element 2

Script Preparation code:

var a = ["hello"];
var b = new Set(a)

Tests:

includes
return a.includes("hello")
lookup
return b.has("hello")
includes miss
return a.includes("world")
lookup miss
return b.has("world")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
includes
lookup
includes miss
lookup miss

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36 Edg/114.0.1823.51

Browser/OS: Chrome 114 on Windows

View result in a separate tab

Test name	Executions per second
includes	10692745.0 Ops/sec
lookup	9617364.0 Ops/sec
includes miss	10843542.0 Ops/sec
lookup miss	11563524.0 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The provided benchmark measures the performance of two different approaches for checking if an element exists in an array or a set.

**Script Preparation Code**

The script preparation code defines two variables:

* `a`: an array containing a single string element, `"hello"`.
* `b`: a new Set object created from the array `a`.

This setup is used to create a test scenario where we can measure the performance of different approaches for checking if an element exists in an array or a set.

**Individual Test Cases**

There are four individual test cases:

1. **`includes`**: This test case checks if `"hello"` exists in the array `a` using the `includes()` method.
2. **`lookup`**: This test case checks if `"hello"` exists in the Set object `b` using the `has()` method.
3. **`includes miss`**: This test case checks if `"world"` exists in the array `a` using the `includes()` method.
4. **`lookup miss`**: This test case checks if `"world"` exists in the Set object `b` using the `has()` method.

**Library: `Set`**

The `Set` data structure is used to store unique elements. A set is an unordered collection of unique values, which makes it efficient for checking membership and existence. In this benchmark, a new Set object is created from the array `a`, allowing us to measure the performance of checking if an element exists in a set.

**Special JS Feature/ Syntax: None**

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

**Options Compared**

The two options being compared are:

1. **`includes()` method**: This method checks if an element exists in an array by iterating through the array elements and returning `true` if the element is found.
2. **`has()` method**: This method checks if an element exists in a Set object by using the underlying hash table data structure to quickly lookup the element.

**Pros and Cons**

* **`includes()` method**:
	+ Pros: widely supported, easy to use, and intuitive.
	+ Cons: can be slower for large arrays due to the iteration process.
* **`has()` method**:
	+ Pros: faster for large sets due to the hash table lookup, and more efficient than iterating through an array.
	+ Cons: less intuitive and less widely supported compared to `includes()`.

**Other Alternatives**

Other alternatives could be:

* Using a library like Lodash or Ramda to provide a more efficient and concise way of checking membership in arrays or sets.
* Implementing a custom lookup algorithm for the Set object, potentially leading to better performance but also increased complexity and maintenance overhead.
* Using a different data structure, such as a hash table or a map, instead of an array or set.

**Benchmark Result Interpretation**

The benchmark result shows that:

* The `has()` method is faster than the `includes()` method for checking if an element exists in both arrays and sets.
* The `lookup miss` test case is slower than the other three test cases, indicating that the `has()` method may not be optimized well for false positives.

Overall, this benchmark provides valuable insights into the performance characteristics of different methods for checking membership in arrays and sets.

Related benchmarks:

set.has vs. array.includes for single element 2 (version: 0)

Comparing performance of: includes vs lookup vs includes miss vs lookup miss

Created: one year ago by: Guest

Jump to the latest result

includes

lookup

includes miss

lookup miss

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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