Benchmark: getOwnPropertyNames vs loop vs cached property names

Script Preparation code:

var obj = {
  $names : ['a','b','c'],
  a:1,
  b:2,
  c:3
}

Tests:

getOwnPropertyNames
var ks = Object.getOwnPropertyNames(obj); var n = 0; for (var i = 0; i < ks.length; i++) { var k = ks[i]; if (k.charAt(0) == '$') continue; n++; }
Cached property names
var ks = obj['$names']; var n = 0; for (var i = 0; i < ks.length; i++) { var k = obj[ks[i]]; n++; }
for in
var n = 0; for (var k in obj) { if (k.charAt(0) == '$') continue; n++; }
Object.keys
var ks = Object.keys(obj); var n = 0; for (var i = 0; i < ks.length; i++) { var k = ks[i]; if (k.charAt(0) == '$') continue; n++; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
getOwnPropertyNames
Cached property names
for in
Object.keys

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and explain what's being tested, the options compared, their pros and cons, and other considerations.

**Benchmark Definition**

The benchmark is defined as: "getOwnPropertyNames vs loop vs cached property names"

This benchmark aims to compare the performance of three different approaches:

1. `getOwnPropertyNames` (Object's built-in method)
2. A manual loop that filters out properties with a `$` prefix
3. Using a cached property name array (`'$names'`) as an alternative

**Options Compared**

Here are the options being compared, along with their pros and cons:

### 1. `getOwnPropertyNames`

* Description: This method returns an array of property names defined directly in the object.
* Pros:
	+ Efficient, as it uses the browser's internal optimization
* Cons:
	+ May include properties not explicitly defined in the object (e.g., inherited properties)
	+ May be slower due to the overhead of the `Object` API

### 2. Manual Loop

* Description: This approach manually loops through the `ks` array and filters out properties with a `$` prefix.
* Pros:
	+ Simple and easy to implement
	+ Does not include inherited properties or properties not explicitly defined in the object
* Cons:
	+ May be slower due to the overhead of the loop and conditional statements

### 3. Cached Property Names (`'$names'`)

* Description: This approach uses an array of cached property names (`'$names'`) to filter out unwanted properties.
* Pros:
	+ Fast, as it avoids the overhead of a loop
	+ Does not include inherited properties or properties not explicitly defined in the object
* Cons:
	+ Requires manual initialization and maintenance of the `$names` array

**Library Usage**

The benchmark uses the `Object` API to access the `getOwnPropertyNames` method. This is a built-in JavaScript library that provides various methods for manipulating objects.

**Special JS Feature/Syntax**

There are no special JavaScript features or syntax used in this benchmark. The code only relies on standard JavaScript constructs and APIs.

**Other Considerations**

When running benchmarks, it's essential to consider the following factors:

* **Hardware**: The type of hardware being tested (e.g., desktop, mobile, GPU-accelerated).
* **Browser/Engine**: The specific browser or engine being used (e.g., Firefox, Chrome, Safari).
* **JavaScript Engine**: The internal JavaScript engine being used by the browser.
* **Cache and Profiling**: Ensure that caching and profiling are enabled to provide accurate results.

**Alternatives**

If you're interested in exploring alternative approaches, consider the following:

1. Use a different property access method, such as `Object.keys()` or `for...in`.
2. Implement your own custom property filtering logic.
3. Compare performance using other benchmarking tools or frameworks (e.g., V8.js, Benchmark.js).

Keep in mind that these alternatives may have their own trade-offs and potential optimizations opportunities.

Latest run results:

Run details: (Test run date: 6 months ago)

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:125.0) Gecko/20100101 Firefox/125.0

Browser/OS: Firefox 125 on Ubuntu

View result in a separate tab

Test name	Executions per second
getOwnPropertyNames	7296244.5 Ops/sec
Cached property names	24212460.0 Ops/sec
for in	16048782.0 Ops/sec
Object.keys	8852489.0 Ops/sec

Related benchmarks:

getOwnPropertyNames vs loop vs cached property names (version: 0)

Comparing performance of: getOwnPropertyNames vs Cached property names vs for in vs Object.keys

Created: 8 years ago by: Guest

Jump to the latest result

getOwnPropertyNames

Cached property names

for in

Object.keys

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):