Benchmark: get content of object

Script Preparation code:

const a = {
    b: true
}

Tests:

use in operation
'b' in a
dot notation
a.b
hasOwnProperty
a.hasOwnProperty('b')

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
use in operation
dot notation
hasOwnProperty

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36 Edg/130.0.0.0

Browser/OS: Chrome 130 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
use in operation	26644836.0 Ops/sec
dot notation	26648416.0 Ops/sec
hasOwnProperty	24781180.0 Ops/sec

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

LLMs can make mistakes. Check important info.

The benchmark defined in the provided JSON aims to evaluate the performance of three different methods of accessing properties of a JavaScript object. The object being tested is a simple one defined as `const a = { b: true }`, which has a single property `b`.

### Test Cases and Comparisons

1. **Use of `in` Operator (`'b' in a`)**
   - **Description**: The `in` operator checks if a property exists in an object. It returns `true` if the specified property is found, both directly on the object and in its prototype chain.
   - **Pros**:
     - It confirms property existence without caring about property value; it can be used to check for properties that may be inherited.
   - **Cons**:
     - It can lead to confusion if the object has inherited properties, as this method returns true even if the property is not directly on the object.
     - Slightly slower due to the additional lookup in the prototype chain.

2. **Dot Notation (`a.b`)**
   - **Description**: The straightforward way to access object properties directly using dot notation. This method retrieves the value of property `b` from object `a`.
   - **Pros**:
     - Simple and concise, making the code easily readable.
     - Fastest access method since it directly retrieves the value from the object without overhead.
   - **Cons**:
     - If the property does not exist, it will return `undefined`, which may require additional checks if property existence is necessary.
     - Note that spaces or invalid characters in property names can't be handled with dot notation.

3. **Using `hasOwnProperty` (`a.hasOwnProperty('b')`)**
   - **Description**: This method checks if the property `b` is a direct property of the object `a` without traversing the prototype chain.
   - **Pros**:
     - Useful for ensuring that the property is defined directly on the object, not inherited from the prototype.
     - Provides clarity about the ownership of properties.
   - **Cons**:
     - Slightly slower than dot notation as it is a method call and has a small overhead.
     - The existence of properties that use control characters or spaces requires the usage of this method instead of dot notation.

### Benchmark Results

The benchmark results show the number of executions per second for each method. The results are as follows:

- **Dot Notation**: 26,648,416 executions per second (fastest)
- **`in` Operator**: 26,644,836 executions per second (slightly slower)
- **`hasOwnProperty` Method**: 24,781,180 executions per second (slowest)

### Other Considerations and Alternatives

- **Alternative Approaches**: 
  - **Bracket Notation**: Instead of using dot notation, one can access properties using brackets (e.g., `a['b']`). This approach is especially beneficial when property names are dynamic or contain special characters.
  - **Object.keys() or Object.hasOwn()**: While not directly tested here, these methods can also be used for property checks and their existence. However, they serve slightly different purposes (e.g., listing properties).
  
- **Performance Implications**: When choosing which method to use, it's important to consider the context in which the property access occurs. For high-frequency access, opting for dot notation can significantly reduce overhead.

This benchmark serves as a helpful guide for software engineers to choose the most efficient way to access object properties in JavaScript, balancing between performance and clarity based on their specific use case.

Related benchmarks:

get content of object (version: 1)

Comparing performance of: use in operation vs dot notation vs hasOwnProperty

Created: one month ago by: Guest

Jump to the latest result

use in operation

dot notation

hasOwnProperty

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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