Benchmark: Object.keys vs Object.getOwnPropertyNames - objects with 100k keys

Script Preparation code:

var obj = {}

let numKeys = 100000;
for (let i = 0; i < numKeys; i++) {
  obj["key_" + i.toString()] = i;
}

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: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; rv:104.0) Gecko/20100101 Firefox/104.0

Browser/OS: Firefox 104 on Windows

View result in a separate tab

Test name	Executions per second
Object.keys	434.7 Ops/sec
Object.getOwnPropertyNames	496.3 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 its options.

**Benchmark Description**

The benchmark is designed to compare the performance of two JavaScript methods: `Object.keys()` and `Object.getOwnPropertyNames()`. These methods are used to retrieve an array of property names (keys) from an object.

**Options Compared**

Two main options are compared:

1. **`Object.keys()`**: This method returns an array of a given object's own enumerable property names. It only includes properties that are directly accessible via the `in` operator.
2. **`Object.getOwnPropertyNames()`**: This method returns an array of all properties (including non-enumerable ones) in a given object.

**Pros and Cons**

*   **`Object.keys()`**
    *   Pros:
        *   Faster performance, as it only includes enumerable properties.
        *   More memory-efficient, as it doesn't include non-enumerable properties.
    *   Cons:
        *   Might not return all keys if the object has non-enumerable properties.
*   **`Object.getOwnPropertyNames()`**
    *   Pros:
        *   Returns all keys (including non-enumerable ones).
    *   Cons:
        *   Slower performance, as it needs to access non-enumerable properties.
        *   More memory-intensive.

**Library and Special Features**

There is no explicit library mentioned in the benchmark definition or test cases. However, `Object.keys()` and `Object.getOwnPropertyNames()` are built-in methods provided by JavaScript itself.

No special features or syntax are used in this benchmark that would require additional explanation.

**Other Alternatives**

For other alternatives to these two methods, you could consider:

*   **`for...in` loop**: You can use a `for...in` loop to iterate over an object's properties. This approach is more flexible but also less efficient.
*   **`Object.values()` and `Object.entries()`**: These methods provide alternative ways to retrieve an array of an object's values or key-value pairs, respectively.

Related benchmarks:

Object.keys vs Object.getOwnPropertyNames - objects with 100k 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):