Benchmark: Test assign vs deconstruct

Script Preparation code:

const a = {id: 12, age: 453, name: "toto", time: new Date()};

Tests:

Assign
const userId = a.id;
Deconstruct + rename
const {id: userId} = a;
Deconstruct simple
const {id} = a;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Assign
Deconstruct + rename
Deconstruct simple

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 22 days ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.36

Browser/OS: Chrome 133 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Assign	163540672.0 Ops/sec
Deconstruct + rename	173290720.0 Ops/sec
Deconstruct simple	176692704.0 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated 6 months ago):

LLMs can make mistakes. Check important info.

The benchmark defined in the provided JSON tests three different approaches for extracting a property from a JavaScript object, specifically the `id` property from an object `a`. The objective is to compare the performance of these different methods: traditional assignment, object destructuring with renaming, and simple object destructuring.

### Test Cases Explained

1. **Assign**
   - **Benchmark Definition**: `const userId = a.id;`
   - **Description**: This approach uses a direct assignment to retrieve the `id` property from the object `a`. It is the most straightforward method, extracting the property without any additional syntax.
   - **Pros**:
     - Simplicity: It is easy to read and understand.
     - Performance: This method is often the fastest due to its direct approach.
   - **Cons**: 
     - Limited scalability: It can become cumbersome when extracting multiple properties from an object, as each must be assigned individually.

2. **Deconstruct + rename**
   - **Benchmark Definition**: `const {id: userId} = a;`
   - **Description**: This technique utilizes JavaScript's object destructuring syntax to extract the `id` property from object `a` while also renaming it to `userId`. 
   - **Pros**:
     - Compactness: This method allows for the extraction of properties in a concise manner.
     - Flexibility: You can rename the properties as needed, which can help avoid naming conflicts.
   - **Cons**:
     - Slightly more complex syntax than direct assignment, which may be less readable for newer developers.
     - Potential performance overhead compared to direct assignment.

3. **Deconstruct simple**
   - **Benchmark Definition**: `const {id} = a;`
   - **Description**: This approach employs object destructuring to retrieve the `id` property directly and assigns it to a variable with the same name.
   - **Pros**:
     - Clean and minimal syntax, particularly useful when dealing with multiple properties at once.
     - Enhances readability when extracting multiple properties since they can all be done in one statement.
   - **Cons**:
     - Similar performance concerns as destructuring with renaming, given the additional syntax.

### Performance Results

Based on the benchmarking results provided, it appears that the fastest method was the simple deconstructing (`Deconstruct simple`), followed closely by destructuring with renaming (`Deconstruct + rename`), and then the direct assignment (`Assign`). Here are the execution rates measured in executions per second:

- **Deconstruct simple**: 10,586,808 executions/second
- **Deconstruct + rename**: 10,572,432 executions/second
- **Assign**: 10,561,109 executions/second

### Considerations

- **Browser and Engine Differences**: Performance can vary across different JavaScript engines and browsers, so results may not be universally applicable. The benchmarks were measured on Chrome (version 130) running on Windows.
- **Context of Usage**: The choice between these methods may depend on the specific context within a codebase. In cases where clarity or maintainability is a priority, destructuring can be preferred despite potential performance trade-offs.

### Alternatives

Other alternatives and considerations for property extraction from objects in JavaScript include:

- **Using Functions**: Wrapping the extraction logic in functions can make code reusable but may incur a performance penalty due to additional function call overhead.
- **Libraries**: While this benchmark does not involve any external libraries, frameworks like Lodash can augment object manipulation capabilities, providing utility functions for deep property extraction or cloning, but they also come with performance costs and added complexity.
- **Uniqueness of Structure**: Depending on how object `a` evolves or is utilized, consider further abstraction such as creating dedicated data access functions or classes to manage how data is accessed and modified.

In summary, the benchmark effectively compares traditional property access with modern JavaScript destructuring techniques, helping developers make informed decisions based on performance implications and code maintainability.

Related benchmarks:

Test assign vs deconstruct (version: 1)

Comparing performance of: Assign vs Deconstruct + rename vs Deconstruct simple

Created: 6 months ago by: Guest

Jump to the latest result

Assign

Deconstruct + rename

Deconstruct simple

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated 6 months ago):