Benchmark: Object.prototype.hasOwnProperty vs obj.hasOwnProperty vs exists check vs 2

Script Preparation code:

window.obj = { a: 2 }

Tests:

Object.prototype.hasOwnProperty
Object.prototype.hasOwnProperty.call(obj, 'a');
obj.hasOwnProperty
obj.hasOwnProperty('a');
null check
obj.hasOwnProperty && obj.hasOwnProperty('a');
null check function
typeof obj.hasOwnProperty === 'function' && obj.hasOwnProperty('a');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.prototype.hasOwnProperty
obj.hasOwnProperty
null check
null check function

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

Let's dive into the benchmark.

**What is being tested?**

The provided JSON represents a JavaScript microbenchmark test case on MeasureThat.net. The test case measures the performance of different approaches to check if an object has a specific property.

The benchmark tests four different methods:

1. `Object.prototype.hasOwnProperty.call(obj, 'a')`
2. `obj.hasOwnProperty('a')`
3. `obj.hasOwnProperty && obj.hasOwnProperty('a')`
4. `typeof obj.hasOwnProperty === 'function' && obj.hasOwnProperty('a')`

**Options being compared:**

These options are compared to determine which approach is the fastest.

1. **`Object.prototype.hasOwnProperty.call(obj, 'a')`**: This method uses the `hasOwnProperty` method on the object's prototype chain and checks if the specified property exists.
2. **`obj.hasOwnProperty('a')`**: This method directly calls the `hasOwnProperty` method on the object itself.
3. **`obj.hasOwnProperty && obj.hasOwnProperty('a')`**: This approach uses a null check ( `obj.hasOwnProperty` ) followed by another call to `hasOwnProperty` to ensure the property exists.
4. **`typeof obj.hasOwnProperty === 'function' && obj.hasOwnProperty('a')`**: This method checks if `hasOwnProperty` is a function before calling it.

**Pros and Cons of each approach:**

1. **`Object.prototype.hasOwnProperty.call(obj, 'a')`**:
	* Pros: Avoids null pointer exceptions (NPEs) by using the prototype chain.
	* Cons: May be slower due to the additional call on the object's prototype.
2. **`obj.hasOwnProperty('a')`**:
	* Pros: Simple and straightforward.
	* Cons: NPE risk if `obj` is null or undefined, which could lead to performance issues in some cases.
3. **`obj.hasOwnProperty && obj.hasOwnProperty('a')`**:
	* Pros: Combines a null check with the actual property existence check.
	* Cons: Adds unnecessary overhead due to the additional call on `hasOwnProperty`.
4. **`typeof obj.hasOwnProperty === 'function' && obj.hasOwnProperty('a')`**:
	* Pros: Checks if `hasOwnProperty` is a function, which can help avoid NPEs.
	* Cons: May be slower due to the additional type check.

**Library and syntax considerations:**

The test case uses the `window.obj` object, which suggests that this benchmark was written for a web environment where the global scope (`window`) is available. The use of `typeof obj.hasOwnProperty === 'function' && obj.hasOwnProperty('a')` implies that the test author wanted to ensure that `hasOwnProperty` is called as a function.

**Special JS features and syntax:**

There are no special JavaScript features or syntax mentioned in this benchmark definition.

**Other alternatives:**

Some alternative approaches that were not tested in this benchmark include:

* Using `in` operator instead of `hasOwnProperty`
* Using `instanceof` to check if the object is a custom instance
* Using `Object.keys()` and checking for the existence of the property
* Using a library like Lodash's `has` function

Keep in mind that these alternative approaches might have different performance characteristics, pros, and cons compared to the methods tested in this benchmark.

Related benchmarks:

Object.prototype.hasOwnProperty vs obj.hasOwnProperty vs exists check vs 2 (version: 0)

Comparing performance of: Object.prototype.hasOwnProperty vs obj.hasOwnProperty vs null check vs null check function

Created: 5 years ago by: Guest

Jump to the latest result

Object.prototype.hasOwnProperty

obj.hasOwnProperty

null check

null check function

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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