Benchmark: 6e8fbee3-9c41-432e-8606-5a5df016e2b1

Script Preparation code:

var obj = {
  "1": 1,
  "2": 2,
  "3": 3,
  "4": 4,
  "5": 5,
  "6": 6,
  "7": 7,
  "8": 8,
  "9": 9,
  "10": 10,
  "11": 11,
  "12": 12,
  "13": 13,
  "14": 14,
  "15": 15,
  "16": 16,
  "17": 17,
  "18": 18,
  "19": 19,
  "20": 20,
  "21": 21,
  "22": 22,
  "23": 23,
  "24": 24,
  "25": 25,
}

for (let value = 26; value < 51; ++value) Object.defineProperty(obj, value, { value })

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:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Measuring JavaScript performance is an essential task for developers, especially when it comes to optimizing code for various browsers and devices.

**Benchmark Definition**

The provided JSON defines two benchmark tests:

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

Both tests use a single variable `obj` initialized with 25 properties (keys) using the following script preparation code:
```javascript
var obj = {
    "1": 1,
    "2": 2,
    ...
    "25": 25
};

for (let value = 26; value < 51; ++value) Object.defineProperty(obj, value, { value });
```
This creates an object `obj` with a fixed number of properties and then dynamically adds more properties using the `Object.defineProperty()` method.

**Options Compared**

The two tests differ in how they access the object's keys:

1. **`Object.keys(obj)`**: This function returns an array of strings containing the property names of the object.
2. **`Object.getOwnPropertyNames(obj)`**: This function returns an array of strings containing the property names and indices of the object.

**Pros and Cons**

*   **`Object.keys()`**:
    *   Pros: It's a built-in method, easy to use, and provides an array of strings (keys) in a single pass.
    *   Cons: The order of keys might not be predictable across different browsers, as the method uses the `toString()` method internally. Additionally, it doesn't provide any information about the property types or descriptors.
*   **`Object.getOwnPropertyNames()`**:
    *   Pros: It returns an array with both property names and indices, which can be useful in certain scenarios. However, it's not as efficient as `Object.keys()` because it needs to access every property descriptor (including non-own properties) of the object.
    *   Cons: The method is less optimized than `Object.keys()`, especially for large objects. Moreover, its results might include both own and non-own properties, which can make debugging more challenging.

**Library Usage**

There are no external libraries used in this benchmark definition.

**Special JS Features or Syntax**

Neither of the tests uses any special JavaScript features or syntax beyond what's required to define a function call (`Object.keys(obj)` and `Object.getOwnPropertyNames(obj)`).

Now that you've been walked through the explanation, let me offer some alternatives:

*   **Benchmarking frameworks**: If you're looking for more structured benchmarking, consider using established frameworks like [Benchmark.js](https://benchmarkjs.com/), which offers a wide range of options for defining benchmarks and running them on multiple browsers.
*   **Custom benchmarking tools**: Depending on your specific needs, you might want to create a custom benchmarking tool using Node.js's `process` object or a third-party library like [benchmark](https://github.com/cjbartholomew/benchmark).

Feel free to ask if there is anything else I can help you with.

Related benchmarks:

6e8fbee3-9c41-432e-8606-5a5df016e2b1 (version: 0)

Comparing performance of: Object.keys vs Object.getOwnPropertyNames

Created: 2 years ago by: Guest

Jump to the latest result

Object.keys

Object.getOwnPropertyNames

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):