Benchmark: set.has vs. array.includes on strings

Script Preparation code:

var a = ["x", "y", "width", "height", "showTrend", "showLabel", "somePropertyWithExtremelyLongName", "originX", "originY", "name"];
var b = new Set(a)

Tests:

includes
return a.includes("somePropertyWithExtremelyLongName")
lookup
return b.has("somePropertyWithExtremelyLongName")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
includes
lookup

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

I'd be happy to explain the benchmark and its results.

**What is tested:**

The provided JSON represents a JavaScript microbenchmark that tests two approaches for searching for a specific string within an array of strings:

1. `array.includes()`: This method checks if a specified value (in this case, "somePropertyWithExtremelyLongName") exists in the given array (`a`).
2. Creating a new `Set` object from the array and then using the `has()` method to check for the presence of the same string.

**Options compared:**

The two options being compared are:

* **Array.includes()**: This is a built-in JavaScript method that allows you to search for a specific value within an array. It returns `true` if the value exists in the array and `false` otherwise.
* **Set-based lookup (b.has())**: In this approach, an array (`a`) is converted into a Set object and then the `has()` method is used to check for the presence of a specific string within that set.

**Pros and cons of each approach:**

* **Array.includes():**
	+ Pros:
		- Fast and efficient (on average, O(n) complexity).
		- Well-supported in modern browsers.
	+ Cons:
		- Can be slower for very large arrays due to the linear search algorithm.
		- May not be suitable for use cases where exact matches are required (e.g., finding a specific string among an array of unique strings).
* **Set-based lookup (b.has()):**
	+ Pros:
		- Generally faster than `array.includes()` for very large arrays, since sets use hash tables to store and retrieve elements quickly.
		- Suitable for use cases where exact matches are required.
	+ Cons:
		- May not be suitable for smaller arrays or arrays with many duplicate values (due to the overhead of creating a set).
		- Requires careful consideration when converting between arrays and sets.

**Library used:**

None explicitly mentioned in the provided benchmark, but it's likely that the `Set` object is created using the built-in JavaScript `Set()` constructor.

**Special JS feature or syntax:**

There doesn't appear to be any special JavaScript features or syntax being used in this benchmark. However, it's worth noting that the use of `extremelyLongString` values might demonstrate a performance characteristic where long strings are more likely to cause issues with certain data structures or algorithms.

**Other alternatives:**

If you were looking for alternative approaches to searching for a specific string within an array, some other options could include:

* Using a regular expression (e.g., `a.includes(new RegExp('somePropertyWithExtremelyLongName'))`) - this can be faster than using `array.includes()` but may also add complexity and potential security risks if not used carefully.
* Creating a trie or prefix tree data structure from the array, which could provide fast lookup times for common prefixes (e.g., "somePrefix-") but might require additional memory and computational resources.

Keep in mind that these alternatives would depend on the specific use case and requirements of your application.

Related benchmarks:

set.has vs. array.includes on strings (version: 0)

Comparing performance of: includes vs lookup

Created: 4 years ago by: Registered User

Jump to the latest result

includes

lookup

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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