Benchmark: Object keys vs getOwnPropertyNames vs entries

Script Preparation code:

window.obj = {error: true, error2: true, error3: true};

Tests:

keys
Object.keys(window.obj).length === 0;
getOwnPropertyNames
Object.getOwnPropertyNames(window.obj).length === 0;
entries
Object.entries(window.obj).length === 0;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
keys
getOwnPropertyNames
entries

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):

LLMs can make mistakes. Check important info.

Measuring performance of JavaScript microbenchmarks is crucial to identify optimization opportunities and ensure that the code runs efficiently in different environments.

**Benchmark Definition JSON**

The benchmark definition represents three test cases:

1.  **`Object.keys(window.obj).length === 0`**: This test case measures the performance of the `Object.keys()` method. It checks if the length of the array returned by `Object.keys()` is equal to 0.
2.  **`Object.getOwnPropertyNames(window.obj).length === 0`**: This test case measures the performance of the `Object.getOwnPropertyNames()` method. It checks if the length of the array returned by this method is equal to 0.
3.  **`Object.entries(window.obj).length === 0`**: This test case measures the performance of the `Object.entries()` method. It checks if the length of the array returned by this method is equal to 0.

**Options Compared**

The benchmark compares the performance of three different methods:

1.  **`Object.keys()`**: Returns an array of a given object's own enumerable property names.
2.  **`Object.getOwnPropertyNames()`**: Returns an array of all properties (including non-enumerable ones) of a given object.
3.  **`Object.entries()`**: Returns an array of a given object's own enumerable string-valued property key-value pairs.

**Pros and Cons of Each Approach**

*   **`Object.keys()`**:
    *   Pros: Efficient, fast, and widely supported by most browsers.
    *   Cons: Does not return non-enumerable properties, which might be relevant in certain situations.
*   **`Object.getOwnPropertyNames()`**:
    *   Pros: Returns all properties (including non-enumerable ones), but can be slower due to its more complex implementation.
    *   Cons: May have performance implications and is less efficient than `Object.keys()`.
*   **`Object.entries()`**:
    *   Pros: More memory-efficient, as it returns a single array of key-value pairs instead of an array of property names.
    *   Cons: Returns non-enumerable properties, which might not be desirable in all cases.

**Library Used**

None explicitly mentioned, but the code snippet uses `window.obj` and `Object` properties from the global scope. These are native JavaScript objects.

**Special JS Feature or Syntax**

No special features or syntax are used in this benchmark.

**Other Alternatives**

For measuring performance of similar methods:

*   **`Object.keys()`**: This is a widely supported method that returns an array of enumerable property names.
*   **`for...in` loop with `hasOwnProperty()`**: A more traditional approach to iterate over object properties, which can be slower but provides more control.

To measure the performance of non-enumerable properties:

*   **`Object.getOwnPropertyNames()`**: As mentioned earlier, this method returns all properties (including non-enumerable ones), but it might have performance implications.
*   **Iterate using `for...in` loop with `hasOwnProperty()`**: This approach provides more control over iterating over non-enumerable properties.

In general, measuring the performance of microbenchmarks requires understanding the specific requirements and constraints of your use case. The choice of method depends on whether you prioritize efficiency, memory usage, or a balance between both.

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36

Browser/OS: Chrome 114 on Windows

View result in a separate tab

Test name	Executions per second
keys	3950479.5 Ops/sec
getOwnPropertyNames	3352462.2 Ops/sec
entries	3652700.8 Ops/sec

Related benchmarks:

Object keys vs getOwnPropertyNames vs entries (version: 0)

Comparing performance of: keys vs getOwnPropertyNames vs entries

Created: 4 years ago by: Registered User

Jump to the latest result

keys

getOwnPropertyNames

entries

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):