Benchmark: Set.prototype.has vs Object.hasOwn

Script Preparation code:

window.myObject = {};
window.mySet = new Set();
for (let i = 1; i < 1001; i++) {
  window.myObject[i] = null;
  window.mySet.add(i);
}

Tests:

Object.hasOwn
for (let i = 1000; i > 0; i--) { Object.hasOwn(window.myObject, i); }
Set.prototype.has
for (let i = 1000; i > 0; i--) { window.mySet.has(i); }

Historical Performance Data aggregated from 6 community runs

Desktop Results:

Firefox 6 runs

Object.hasOwn

5K/s

Set.prototype.has

5K/s

View exact numbers

✓ Object.hasOwn: 4,737 ops/sec
• Set.prototype.has: 4,514 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.hasOwn
Set.prototype.has

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/605.1.15 (KHTML, like Gecko) Version/18.4 Safari/605.1.15

Browser/OS: Safari 18 on Mac OS X 10.15.7

View result in a separate tab

Set.prototype.has

1.8M/s

Object.hasOwn

12K/s

View exact numbers

Test name	Executions per second
✓ Set.prototype.has	1,843,018 Ops/sec
Object.hasOwn	11,744 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the JavaScript microbenchmark.

**What is being tested?**

The provided JSON represents two test cases, comparing the performance of `Set.prototype.has` and `Object.hasOwn`. Both methods are used to check if an object has a certain property. The benchmark measures which method is faster in terms of executions per second.

**Options compared:**

The comparison is between:

1. **`Set.prototype.has`**: This method is part of the Set interface, introduced in ECMAScript 2015 (ES6). It checks if an element with the specified value exists in the set.
2. **`Object.hasOwn`**: This method is a part of the Object prototype, also introduced in ES6. It returns a boolean indicating whether the object has the specified property.

**Pros and Cons:**

1. **`Set.prototype.has`**:
	* Pros: More efficient for large sets, as it uses a hash table under the hood, making lookups O(1) on average.
	* Cons: May be slower for small sets or single-element sets due to overhead of creating and managing the underlying data structure.
2. **`Object.hasOwn`**:
	* Pros: Widely supported across browsers and platforms, as it's a part of the Object prototype.
	* Cons: Less efficient than `Set.prototype.has`, especially for large datasets.

**Library usage:**

The benchmark uses the `window.myObject` and `window.mySet` objects, which are created using the provided script preparation code. These objects are used to simulate a scenario where you need to check if an object has a certain property.

**Special JS feature or syntax:**

There is no special JavaScript feature or syntax being tested in this benchmark.

**Other alternatives:**

If `Object.hasOwn` was not available, other alternatives might have been explored, such as:

* Using the `in` operator (`i in window.mySet`) to check if an element exists in the set.
* Implementing a custom lookup function using an array or hash table.

However, since `Object.hasOwn` is widely supported and efficient for checking property existence, it's likely that this alternative was not considered in this benchmark.

Set.prototype.has vs Object.hasOwn (version: 0)

Comparing performance of: `Object.hasOwn vs Set.prototype.has`

Created: 3 years ago by: Guest

Go to the latest result

Object.hasOwn

Set.prototype.has

Historical Performance Data aggregated from 6 community runs

Desktop Results:

Firefox 6 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Set.prototype.has vs Object.hasOwn (version: 0)

Comparing performance of: Object.hasOwn vs Set.prototype.has

Created: 3 years ago by: Guest

Go to the latest result

Object.hasOwn

Set.prototype.has

Historical Performance Data aggregated from 6 community runs

Desktop Results:

Firefox 6 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Related benchmarks

Comparing performance of: `Object.hasOwn vs Set.prototype.has`