Benchmark: DefineProperties vs assignment

Tests:

Define properties
for (var i=0; i<10000; i++) { const x = Object.defineProperties(Object.create(null), { ns: {value: "ns"}, tags: {value: Object.create(null)}}); }
assignment
for (var i=0; i<10000; i++) { const x = Object.create(null) x.ns = "ns" x.tags = Object.create(null); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Define properties
assignment

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 9 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/139.0.0.0 Safari/537.36 Edg/139.0.0.0

Browser/OS: Chrome 139 on Windows

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Test name	Executions per second
Define properties	453.3 Ops/sec
assignment	3960.4 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated one year ago):

LLMs can make mistakes. Check important info.

The benchmark described compares the performance of two approaches for creating objects in JavaScript: using `Object.defineProperties` versus using direct assignment to define properties on an object. Here’s a breakdown of what is being tested, including the pros and cons of each approach and additional considerations.

### Approaches Compared

1. **Using `Object.defineProperties`:**
   - **Test Case Code:**
     ```javascript
     for (var i=0; i<10000; i++) {
         const x = Object.defineProperties(Object.create(null), { 
             ns: { value: "ns" }, 
             tags: { value: Object.create(null) }
         });
     }
     ```
   - **Description:**
     This approach involves using `Object.defineProperties`, which allows for the definition of property properties (like `enumerable`, `configurable`, and `writable` in addition to just the value).

2. **Direct Assignment:**
   - **Test Case Code:**
     ```javascript
     for (var i=0; i<10000; i++) {
         const x = Object.create(null);
         x.ns = "ns";
         x.tags = Object.create(null);
     }
     ```
   - **Description:**
     This method simply assigns properties directly to the object using the assignment syntax.

### Performance Results

The benchmark results show significant differences in the execution speed of the two methods:

- **Direct Assignment:**
  - Executions Per Second: **3286.20**
  - Faster and more efficient for this use case.

- **Using `Object.defineProperties`:**
  - Executions Per Second: **411.03**
  - Much slower, but provides more control over property characteristics.

### Pros and Cons

#### `Object.defineProperties`
- **Pros:**
  - Allows detailed control over the property characteristics beyond just value. For instance, you can make a property non-writable or non-enumerable.
  - Useful for defining properties with specific behavior, which can be important in certain object-oriented designs.

- **Cons:**
  - Slower in performance, as evidenced by the benchmark results.
  - More verbose and complex, which can lead to more boilerplate code.

#### Direct Assignment
- **Pros:**
  - Faster and more performant for simple property assignments.
  - Easier and more intuitive to read and write for straightforward property creation.
  
- **Cons:**
  - Less control over the behavior of the properties (all properties will be writable and enumerable by default).

### Other Considerations
- This benchmark highlights a common decision point developers face regarding performance versus flexibility. For scenarios requiring simple object creation with no special property behavior, direct assignment is preferable.
- In contrast, if an application requires encapsulation of data and strict control over property attributes, `Object.defineProperties` could be warranted despite the performance hit.
  
### Alternatives
- Other ways to manage properties and creation of objects in JavaScript include:
  - **Object literals:** Using curly braces for quick and simple object creation.
  - **Class syntax:** Defining classes with the `class` keyword to create blueprints for objects.
  - **Factory functions:** Using functions to create and return objects, providing flexibility and encapsulation.
  - **Proxy:** Using the Proxy object for more sophisticated control over property access and modification.

In conclusion, the choice between using `Object.defineProperties` and direct assignment should be informed by the specific requirements of the application regarding performance and property control.

Related benchmarks:

DefineProperties vs assignment (version: 1)

Comparing performance of: Define properties vs assignment

Created: one year ago by: Guest

Jump to the latest result

Define properties

assignment

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated one year ago):