Benchmark: Object defineProperty on class

Script Preparation code:

    var DefineProperty = /** @class */ (function () {
        function DefineProperty() {
            Object.defineProperty(this, "b", {
                enumerable: true,
                configurable: true,
                writable: true,
                value: 2
            });
        }
        return DefineProperty;
    }());
    var RawAccess = /** @class */ (function () {
        function RawAccess() {
            this.b = 2;
        }
        return RawAccess;
    }());

Tests:

defineProperty
var obj = new DefineProperty();
Raw access
var obj = new RawAccess()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
defineProperty
Raw access

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:128.0) Gecko/20100101 Firefox/128.0

Browser/OS: Firefox 128 on Windows

View result in a separate tab

Test name	Executions per second
defineProperty	24881636.0 Ops/sec
Raw access	82309400.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark definition is a JSON object that describes two different approaches to accessing the value of `b` on an object. There are two classes: `DefineProperty` and `RawAccess`.

*   `DefineProperty`: This class uses the `Object.defineProperty()` method to define a property `b` on the class itself, rather than on any instances of the class. The property has the following attributes:
    *   `enumerable`: Set to `true`, meaning that this property can be accessed using the `for...in` loop or as an own accessor property.
    *   `configurable`: Set to `true`, meaning that this property's configuration can be changed at runtime.
    *   `writable`: Set to `true`, meaning that this property's value can be changed at runtime.
    *   `value`: Set to `2`, which is the initial value of this property.

*   `RawAccess`: This class does not use any special methods or syntax. Instead, it simply initializes a property named `b` on the class itself with the value `2`.

**Comparison**

The benchmark compares the performance of two approaches:

1.  **DefineProperty**: Uses `Object.defineProperty()` to define the property.
    *   Pros:
        *   Provides explicit control over the property's attributes (e.g., whether it can be enumerated or modified).
        *   Can be useful in scenarios where these attributes need to be customized.
    *   Cons:
        *   May introduce additional overhead due to the use of `Object.defineProperty()`.
2.  **RawAccess**: Does not use any special methods or syntax.
    *   Pros:
        *   Typically has less overhead compared to using a custom property definition mechanism.
        *   Simplifies code and can lead to better maintainability.
    *   Cons:
        *   May have performance differences depending on the browser's property access handling.

**Library**

There is no library used in this benchmark. The `Object.defineProperty()` method is a standard JavaScript API for defining properties on objects.

**Special JS Feature/Syntax**

The benchmark uses a feature called **"JSDoc comments"**, which is a syntax for documenting and generating documentation from JavaScript source code. JSDoc comments are used to provide metadata about the classes, methods, and variables in the code, such as their names and descriptions. In this case, JSDoc comments are used to generate documentation comments for the `DefineProperty` and `RawAccess` classes.

**Alternatives**

Other alternatives for defining properties on objects include:

1.  **Setter and getter functions**: Instead of using `Object.defineProperty()`, you can define a setter function that modifies the property's value, and a getter function that returns the property's value.
2.  **Property getters and setters as methods**: You can create methods on the class that return or modify the property's value, rather than defining it directly on the object.

In general, the choice of approach depends on your specific requirements, performance considerations, and coding style preferences.

Related benchmarks:

Object defineProperty on class (version: 0)

Comparing performance of: defineProperty vs Raw access

Created: 5 years ago by: Guest

Jump to the latest result

defineProperty

Raw access

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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