Benchmark: hasOwnProperty speed

Script Preparation code:

var obj = {}, id;
for (let i = 0; i <= 100; i++){
  obj['param'+i] = i;
}

let hasOwnProperty = Object.prototype.hasOwnProperty;

Tests:

hasOwnProperty call
for(id in obj) { if(hasOwnProperty.call(obj, id)) {} }
hasOwnProperty regular
for(id in obj) { if(obj.hasOwnProperty(id)) {} }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
hasOwnProperty call
hasOwnProperty regular

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/117.0.0.0 Safari/537.36

Browser/OS: Chrome 117 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
hasOwnProperty call	45661.0 Ops/sec
hasOwnProperty regular	73345.6 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 benchmark and explain what's being tested, compared, and their pros and cons.

**Benchmark Definition:**
The benchmark definition is provided in JSON format, which defines two test cases for measuring the speed of accessing an object property using different approaches. The script preparation code initializes a large object `obj` with 101 properties, each assigned a unique integer value from 0 to 100.

**Test Cases:**

1. **hasOwnProperty call**: This test case uses the `hasOwnProperty.call()` method to check if a property exists in an object. Specifically, it loops through the object's properties using a `for...in` loop and checks if each property is present using `hasOwnProperty.call(obj, id)`.
2. **hasOwnProperty regular**: This test case uses the `hasOwnProperty()` method directly on the object to check if a property exists. It also loops through the object's properties using a `for...in` loop and checks if each property is present using `obj.hasOwnProperty(id)`.

**Comparison:**
The benchmark tests the performance difference between two approaches:

* Using `hasOwnProperty.call()`, which takes an additional argument (`this` or `object`) to indicate the object being searched.
* Using `hasOwnProperty()` directly on the object, without any additional arguments.

**Pros and Cons:**

* **hasOwnProperty call**:
	+ Pros:
		- More explicit and flexible, as it allows for easy testing of different objects.
		- Can be useful when working with complex object hierarchies or when need to pass an object reference separately.
	+ Cons:
		- Requires additional function call overhead due to the second argument.
* **hasOwnProperty regular**:
	+ Pros:
		- Faster, as it only requires a single function call without any additional arguments.
		- More concise and idiomatic in most cases.
	+ Cons:
		- May be less explicit or flexible than `hasOwnProperty.call()`, especially when working with complex objects.

**Library/Additional Features:**
There is no library mentioned in the benchmark definition. However, the `Object.prototype.hasOwnProperty()` method is used, which is a part of the JavaScript standard library.

**Special JS feature/syntax:** None are explicitly mentioned or utilized in this benchmark.

**Other Alternatives:**

* Other methods for checking property existence, such as using a simple `in` operator (`in` vs. `hasOwnProperty()`) or `typeof obj[id] === 'undefined'`.
* Using modern JavaScript features like `Object.hasOwn()` (supporting ES6+ syntax) or arrow functions to simplify the comparison.

Keep in mind that these alternatives might have different performance characteristics, and their usage depends on specific use cases and requirements.

Related benchmarks:

hasOwnProperty speed (version: 0)

Comparing performance of: hasOwnProperty call vs hasOwnProperty regular

Created: 6 years ago by: Guest

Jump to the latest result

hasOwnProperty call

hasOwnProperty regular

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):