Benchmark: in vs hasOwnProperty

Script Preparation code:

var obj = { a: 5, b: 6, c: 7 };

Tests:

in
'a' in obj; 'b' in obj; 'c' in obj;
property
Object.hasOwnProperty.call(obj, 'a'); Object.hasOwnProperty.call(obj, 'b'); Object.hasOwnProperty.call(obj, 'c');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
in
property

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's dive into the world of MeasureThat.net and explore what's being tested in this benchmark.

**Benchmark Definition**

The provided JSON represents a JavaScript microbenchmark that compares two approaches for checking if a property exists in an object:

1. **"in"**: Using the "in" operator to check if a property exists.
2. **"property"**: Using the `Object.hasOwnProperty.call()` method to check if a property exists.

**Options Compared**

The benchmark is comparing two options:

* **Option 1: "in"**
	+ This option uses the "in" operator, which returns a boolean value indicating whether the property exists in the object.
	+ The "in" operator is a built-in JavaScript operator that checks if a key exists in an object.
* **Option 2: "property"**
	+ This option uses the `Object.hasOwnProperty.call()` method, which returns a boolean value indicating whether the specified property exists on the specified object.

**Pros and Cons**

Here are some pros and cons of each approach:

* **"in" Operator**
	+ Pros:
		- Concise and easy to read.
		- Fast, as it's a built-in operator.
	+ Cons:
		- May not be as clear or explicit as using `Object.hasOwnProperty.call()`.
		- Can lead to unexpected behavior if the property name is modified accidentally (e.g., assigning to the property instead of checking for its existence).
* **`Object.hasOwnProperty.call()` Method**
	+ Pros:
		- More explicit and clear than using the "in" operator.
		- Provides better error handling, as it explicitly checks for property existence.
	+ Cons:
		- May be slower than using the "in" operator due to additional function call overhead.

**Other Considerations**

When writing this benchmark, MeasureThat.net likely aimed to create a fair comparison between two approaches. However, it's worth noting that in real-world scenarios, you may want to use both methods depending on your specific requirements and performance considerations.

**Library and Special JS Features**

In this benchmark, no libraries are used. Additionally, there are no special JavaScript features or syntax mentioned. The code is straightforward and uses only basic JavaScript constructs.

**Other Alternatives**

If you were to write a similar benchmark, you could consider adding additional options, such as:

* Using `Object.keys()` to iterate over object properties.
* Using `for...in` loops to iterate over object properties.
* Using template literals or string interpolation for dynamic property names.
* Using other libraries like Lodash or Ramda for property existence checks.

These alternatives would introduce additional complexity and potential performance variations, but they might be relevant in specific scenarios where you need more advanced property existence checking mechanisms.

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:78.0) Gecko/20100101 Firefox/78.0

Browser/OS: Firefox 78 on Mac OS X 10.11

View result in a separate tab

Test name	Executions per second
in	24487320.0 Ops/sec
property	9878447.0 Ops/sec

Related benchmarks:

in vs hasOwnProperty (version: 0)

Comparing performance of: in vs property

Created: 3 years ago by: Guest

Jump to the latest result

in

property

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):