Benchmark: ObjectDefineProperty

Script Preparation code:

const obj = {};
obj.data = {
  firstName: 'John',
  lastName: 'Doe',
};

// 定义带有 getter 的属性
Object.defineProperty(obj, 'name', {
  get() {
    return this.data.firstName;
  },
});

Tests:

One
const obj = {}; obj.data = { firstName: 'John', lastName: 'Doe', }; // 定义带有 getter 的属性 Object.defineProperty({}, 'name', { get() { return this.data.firstName; }, }); const temp = {}; for (let i = 0; i < 1000000; i++) { temp[i.toString()] = obj.data.firstName; }
Two
const obj = {}; obj.data = { firstName: 'John', lastName: 'Doe', }; // 定义带有 getter 的属性 Object.defineProperty(obj, 'name', { get() { return this.data.firstName; }, }); const temp = {}; for (let i = 0; i < 1000000; i++) { temp[i.toString()] = obj.name; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
One
Two

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.

**Overview of the Benchmark**

The provided benchmark measures the performance difference between two approaches to defining getter properties in JavaScript objects.

**Script Preparation Code Explanation**

The script preparation code defines an object `obj` with a nested property `data`, which contains another object with two properties: `firstName` and `lastName`. Additionally, it defines a getter property called `name` on the `obj` object using `Object.defineProperty()`. The getter returns the value of `this.data.firstName`.

**Html Preparation Code Explanation**

There is no HTML preparation code provided for this benchmark.

**Benchmark Definition Explanation**

The benchmark definition is simply the script preparation code, which defines two objects: one with a getter property `name`, and another without it. The latter object is used to create an array of 1 million elements, where each element is assigned the value of the `obj.name` getter or `obj.data.firstName`.

**Options Compared**

Two options are compared in this benchmark:

1. **Defining getter properties on objects**: This option uses `Object.defineProperty()` to define a getter property called `name` on the `obj` object.
2. **Accessing getter properties through arrays**: This option creates an array of 1 million elements and assigns each element with either the value of the `obj.name` getter or `obj.data.firstName`.

**Pros and Cons**

* **Defining getter properties on objects**:
	+ Pros: More explicit and maintainable way to define getter properties.
	+ Cons: May incur additional overhead due to the definition process.
* **Accessing getter properties through arrays**:
	+ Pros: Can be faster for large datasets, as accessing array elements is typically optimized by the browser.
	+ Cons: Requires an additional object creation and indexing step, which may introduce unnecessary complexity.

**Library and Syntax Explanation**

There are no libraries used in this benchmark. However, it uses some JavaScript syntax features, such as:

* `Object.defineProperty()`: defines a property descriptor on an object.
* Arrow functions ( implicit, e.g., `get() { return this.data.firstName; }` )
* Template literals (e.g., `"name"` )

**Device and Browser Considerations**

The benchmark results are provided for Chrome 119 running on Windows 10. The device platform is desktop, which may affect the performance results due to differences in caching, memory management, and other system resources.

**Other Alternatives**

If you're interested in exploring alternative approaches or testing different scenarios, here are some suggestions:

* Use a different getter property name or syntax.
* Experiment with different data structures, such as arrays of objects or custom classes.
* Test the performance of the benchmark on different browsers or devices.
* Introduce additional complexity, such as nested getters or multiple object assignments.

Related benchmarks:

ObjectDefineProperty (version: 0)

Comparing performance of: One vs Two

Created: 2 years ago by: Registered User

Jump to the latest result

One

Two

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):