Benchmark: Object.keys vs Object.getOwnPropertyNames - objects with 0 keys

Script Preparation code:

var obj = {}

Tests:

Object.keys
Object.keys(obj);
Object.getOwnPropertyNames
Object.getOwnPropertyNames(obj)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.keys
Object.getOwnPropertyNames

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:132.0) Gecko/20100101 Firefox/132.0

Browser/OS: Firefox 132 on Windows

View result in a separate tab

Test name	Executions per second
Object.keys	27626006.0 Ops/sec
Object.getOwnPropertyNames	27806294.0 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 definition and its results to understand what is being tested.

**Benchmark Definition:**

The benchmark measures the performance difference between two methods to get the keys of an empty object:

1. `Object.keys(obj);`
2. `Object.getOwnPropertyNames(obj);`

Both methods are used to retrieve the property names of an object, but they behave slightly differently in certain cases.

**Options Compared:**

Two options are being compared:

1. **`Object.keys(obj)`**: Returns a sorted array of strings containing the property names of an object.
2. **`Object.getOwnPropertyNames(obj)`**: Returns an array of all properties (including non-enumerable ones) of an object, in the same order they appear in the original source code.

**Pros and Cons:**

1. **`Object.keys(obj)`**:
	* Pros:
		+ Only returns enumerable property names.
		+ Faster performance, as it only iterates over the object's own properties.
	* Cons:
		+ Does not return non-enumerable properties (e.g., those inherited from prototypes).
2. **`Object.getOwnPropertyNames(obj)`**:
	* Pros:
		+ Returns all properties (enumerable and non-enumerable) of an object.
	* Cons:
		+ Slower performance, as it needs to iterate over the entire prototype chain.

**Library and Purpose:**

None of the methods use any external libraries in this benchmark. They are both part of the JavaScript standard library.

**Special JS Feature or Syntax:**

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

**Other Alternatives:**

If you need to compare the performance of other methods for getting object keys, some alternatives might include:

* `Object.getOwnPropertyDescriptors(obj)`: Returns an object containing the property descriptors of an object.
* `Reflect.ownKeys(obj)`: Returns a sequence of all own property names (including non-enumerable ones) of an object.

Keep in mind that these alternatives may have different performance characteristics depending on the specific use case and JavaScript version.

**Benchmark Preparation Code:**

The preparation code is simple:
```javascript
var obj = {};
```
This creates an empty object `obj` for both tests to operate on.

**Individual Test Cases:**

There are two test cases:

1. **`Object.keys(obj)`**: Tests the performance of using `Object.keys()` to get the keys of an empty object.
2. **`Object.getOwnPropertyNames(obj)`**: Tests the performance of using `Object.getOwnPropertyNames()` to get the keys of an empty object.

The benchmark results show that, as expected, `Object.keys()` is faster than `Object.getOwnPropertyNames()`, especially for large objects or when running on desktop platforms with a Linux operating system.

Related benchmarks:

Object.keys vs Object.getOwnPropertyNames - objects with 0 keys (version: 0)

Comparing performance of: Object.keys vs Object.getOwnPropertyNames

Created: 3 years ago by: Guest

Jump to the latest result

Object.keys

Object.getOwnPropertyNames

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):