Benchmark: hasown vs undefined

Tests:

hasown existing
const data = { foo: 3, }; let res = Object.hasOwn(data, foo);
hasown missing
const data = { foo: 3, }; let res = Object.hasOwn(data, bar);
undefined existing
const data = { foo: 3, }; let res = data.foo === undefined;
undefined missing
const data = { foo: 3, }; let res = data.bar === undefined;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
hasown existing
hasown missing
undefined existing
undefined missing

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark and its options, explaining what's tested, pros and cons of each approach, and any special considerations.

**Benchmark Definition**

The benchmark measures the performance difference between `Object.hasOwn()` (introduced in ECMAScript 2015) and a direct comparison using the `===` operator when checking if an object property exists or is undefined.

**Script Preparation Code** and **Html Preparation Code**: Neither of these fields are provided, which suggests that the benchmark assumes that the test cases can be executed directly without any additional setup.

**Individual Test Cases**

There are four test cases:

1. **hasown existing**: Tests if `Object.hasOwn()` returns true when checking for an existing property with a known name (`foo`).
2. **hasown missing**: Tests if `Object.hasOwn()` returns false when checking for a non-existent property with a known name (`bar`).
3. **undefined existing**: Tests if `data.foo === undefined` returns true when the property does not exist.
4. **undefined missing**: Tests if `data.bar === undefined` returns false when the property exists.

**Options Compared**

The benchmark compares the performance of two approaches:

1. **Direct Comparison (`===`)**: This approach uses a direct comparison to check if a property exists or is undefined.
2. **Object.hasOwn()**: This approach uses the `Object.hasOwn()` method, which was introduced in ECMAScript 2015.

**Pros and Cons**

* **Direct Comparison (`===`)`:
	+ Pros: widely supported across older browsers, easy to understand.
	+ Cons: may lead to slower performance due to the additional comparison step.
* **Object.hasOwn()**:
	+ Pros: more efficient than direct comparison for modern browsers that support it.
	+ Cons: not supported in older browsers (pre-ECMAScript 2015).

**Special Considerations**

The benchmark uses a test case with a variable name (`foo` and `bar`) to demonstrate the difference between `Object.hasOwn()` and direct comparison. The use of `const data = { foo: 3, };` ensures that the property exists for the first test case.

**Library Used (if applicable)**

None of the provided benchmarks rely on a specific library. However, the `Object.hasOwn()` method is a built-in part of the ECMAScript standard and is not dependent on any external libraries.

**Other Alternatives**

If you need to check if a property exists or is undefined in older browsers that do not support `Object.hasOwn()`, you can use a direct comparison (`===`) as shown in the test cases. For more efficient performance, consider using `Object.hasOwn()` in modern browsers that support it.

Keep in mind that the benchmark results show varying performance between different browsers and devices, highlighting potential areas for optimization or feature compatibility concerns.

Latest run results:

Run details: (Test run date: 5 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36

Browser/OS: Chrome 126 on Windows

View result in a separate tab

Test name	Executions per second
hasown existing	0.0 Ops/sec
hasown missing	0.0 Ops/sec
undefined existing	14042469.0 Ops/sec
undefined missing	14524279.0 Ops/sec

Related benchmarks:

hasown vs undefined (version: 0)

measures hasown vs undefined speed

Comparing performance of: hasown existing vs hasown missing vs undefined existing vs undefined missing

Created: 5 months ago by: Guest

Jump to the latest result

hasown existing

hasown missing

undefined existing

undefined missing

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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