Benchmark: undefined vs. hasOwnProperty2

Script Preparation code:

var obj = { a: 1, b: 2, c: 3, d: { a: 1, b: 2, b: 3, d: 4 }, e: 5 };

Tests:

undefined
if(obj.d){};
hasOwnProperty
if(obj.hasOwnProperty('d')){}

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
undefined
hasOwnProperty

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.181 Safari/537.36

Browser/OS: Chrome 66 on Windows

View result in a separate tab

Test name	Executions per second
undefined	11477141.0 Ops/sec
hasOwnProperty	10355386.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**What is being tested?**

The provided JSON represents a benchmark for object lookup performance using two different approaches: `undefined` and `hasOwnProperty`. The test case checks how quickly these two methods can be used to check if a property exists in an object.

**Options compared:**

Two options are being compared:

1. **Using `undefined`**: This approach involves checking if a property exists by trying to access it, resulting in `undefined` if the property doesn't exist.
2. **Using `hasOwnProperty()`**: This approach is specifically designed for this purpose and checks if the object has the specified property without throwing an error.

**Pros and Cons:**

1. **Using `undefined`**:
	* Pros: Lightweight, easy to implement, and doesn't require additional libraries or function calls.
	* Cons: Can be slower than `hasOwnProperty()` due to the overhead of checking for existence and then retrieving the value.
2. **Using `hasOwnProperty()`**:
	* Pros: Optimized for this specific use case, faster than using `undefined`, and eliminates the need for additional checks or function calls.
	* Cons: Requires knowledge of the object's prototype chain and may not be as performant in cases where the object is deeply nested.

In general, `hasOwnProperty()` is a better choice when writing JavaScript code, especially for performance-critical applications. However, using `undefined` can still be beneficial in certain situations, such as when working with legacy browsers or environments that don't support `hasOwnProperty()`.

**Library and its purpose**

The `Object.prototype.hasOwnProperty()` method is a built-in JavaScript method that checks if an object has the specified property without throwing an error. It's optimized for performance and is used extensively throughout the JavaScript ecosystem.

**Special JS feature or syntax**

None of the provided test cases use special JavaScript features or syntax. They focus on simple, basic operations to measure the performance difference between `undefined` and `hasOwnProperty()`.

**Other alternatives**

If you're interested in exploring alternative approaches for object lookup performance, consider the following:

1. **Using `in`**: The `in` operator checks if a property exists in an object's prototype chain.
2. **Using `has()` methods**: Some modern JavaScript engines and frameworks offer `has()` methods that can be used to check if an object has a specific property.
3. **Optimized libraries and modules**: There are various optimized libraries and modules available, such as `fast-has` or `property-is`, that provide faster and more efficient ways to check for properties in objects.

Keep in mind that these alternatives might come with additional dependencies, complexity, or performance overhead, so it's essential to evaluate their suitability based on your specific use case.

Related benchmarks:

undefined vs. hasOwnProperty2 (version: 0)

Object lookup performance

Comparing performance of: undefined vs hasOwnProperty

Created: 6 years ago by: Guest

Jump to the latest result

undefined

hasOwnProperty

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):