Benchmark: set.has vs. Object key lookup for real

Script Preparation code:

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

Tests:

set.has
return a.has(9)
key lookup
return !!b['9']

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
set.has
key lookup

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; rv:109.0) Gecko/20100101 Firefox/118.0

Browser/OS: Firefox 118 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
set.has	507369184.0 Ops/sec
key lookup	535082816.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark compares two approaches to check if an element exists in a Set data structure:

1. `set.has` (lookup through the `Set` object)
2. Key lookup using the `!!` operator on the `b` object

**Options Compared**

* `set.has`: Uses the `has()` method provided by the `Set` class to check if an element exists in the set.
* Key lookup: Uses the `!!` operator to check if a property exists on the `b` object.

**Pros and Cons of Each Approach**

* `set.has`:
	+ Pros:
		- Fast and efficient, as it uses a hash table internally to store the elements.
		- Provides accurate results, as it checks for exact equality with the element.
	+ Cons:
		- Requires an additional call to the `has()` method, which might incur some overhead.
* Key lookup (`!!` operator):
	+ Pros:
		- Simple and concise code that doesn't require any additional methods or calls.
		- Can be faster than using `set.has`, as it only requires a simple property access.
	+ Cons:
		- May produce false positives if the element is not an exact match (e.g., due to typos or differences in formatting).
		- Requires care when working with objects, as the `!!` operator can be sensitive to nuances in object creation and behavior.

**Library and Special JS Features**

* The benchmark uses the `Set` class from the JavaScript standard library. This is a built-in data structure that provides efficient lookup, insertion, and removal of elements.
* There is no special JavaScript feature or syntax being tested in this benchmark. However, it's worth noting that some older browsers may not support the `Set` class or may have quirks when using it.

**Alternative Approaches**

Other ways to check if an element exists in a Set could include:

1. Using a loop to iterate over the elements of the set.
2. Using a library like Lodash's `hasIn` function, which provides a more concise and expressive way to perform key lookups on objects.
3. Using a custom implementation that converts the set to an object or array for faster lookup.

However, these alternatives may not provide the same level of performance as using the built-in `Set` class or the simple key lookup approach (`!!` operator).

**Benchmarking Considerations**

When benchmarking this type of test case, it's essential to consider factors like:

* The size and complexity of the data being stored in the set.
* The frequency and distribution of element lookups.
* The specific requirements and constraints of your application (e.g., performance, accuracy, memory usage).

By considering these factors and choosing the right approach for your use case, you can optimize your code for better performance and efficiency.

Related benchmarks:

set.has vs. Object key lookup for real (version: 0)

Comparing performance of: set.has vs key lookup

Created: one year ago by: Guest

Jump to the latest result

set.has

key lookup

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):