Benchmark: desctructuring object keys vs access via dot

Script Preparation code:

const data = Array.from({length: 1_000_000}, () => ({
    a: Math.random(),
    b: Math.random(),
    c: Math.random(),
}));

Tests:

Destructuring
let sum1 = 0; for (let i = 0; i < data.length; i++) { const {a, b, c} = data[i]; sum1 += a + b + c; }
Dot notation
let sum2 = 0; for (let i = 0; i < data.length; i++) { const obj = data[i]; sum2 += obj.a + obj.b + obj.c; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Destructuring
Dot notation

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:137.0) Gecko/20100101 Firefox/137.0

Browser/OS: Firefox 137 on Windows

View result in a separate tab

Test name	Executions per second
Destructuring	287.2 Ops/sec
Dot notation	308.8 Ops/sec

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

LLMs can make mistakes. Check important info.

The benchmark in question compares two different approaches for accessing object properties in JavaScript: using destructuring assignment versus accessing properties via dot notation. Here’s a breakdown of each approach, their pros and cons, and other considerations based on the benchmark data provided.

### Benchmark Overview

1. **Destructuring Assignment**
   - This method involves extracting multiple properties from an object and assigning them to variables in a single statement. In this case, for each object in the `data` array, the properties `a`, `b`, and `c` are destructured.
   - **Code Example:**
     ```javascript
     const {a, b, c} = data[i];
     ```

2. **Dot Notation**
   - This method accesses object properties directly by utilizing the dot operator for each property. For the same objects, the properties are accessed one by one.
   - **Code Example:**
     ```javascript
     const obj = data[i];
     sum2 += obj.a + obj.b + obj.c;
     ```

### Results of the Benchmark
The benchmark results show that the dot notation approach executed 308.78 times per second, while the destructuring approach executed 287.24 times per second.

### Pros and Cons

#### Destructuring Assignment
- **Pros:**
  - Improved readability: The intent to extract multiple properties is clear and concise.
  - Less boilerplate: Reduces repetitive access patterns for familiar properties.
  
- **Cons:**
  - Slightly lower performance as shown in the benchmark results, especially when dealing with a large array of objects since destructuring can introduce overhead due to variable creation.

#### Dot Notation
- **Pros:**
  - Better performance (as indicated by the benchmark results): Generally faster when accessing properties compared to destructuring, especially in tight loops.
  - Familiar syntax and straightforward for those accustomed to traditional object property access.

- **Cons:**
  - Increased verbosity: Requires more code to achieve the same effect as destructuring (multiple accesses for every property).
  
### Other Considerations
- **Use Case Context:** The choice between destructuring and dot notation can depend on the specific context of usage. For instance, if performance is critical in a tight loop where many objects are processed, dot notation might be preferable. In contrast, for clearer and maintainable code, particularly when working with fewer properties or in smaller scopes, destructuring could be beneficial.
  
- **Browser Compatibility:** Both approaches are widely supported across modern browsers. However, developers should always test performance in their specific environments, as results may vary based on the implementation of JavaScript engines.

### Alternatives
Other alternatives for accessing properties include:
- **Bracket Notation:** Useful when property names are dynamic or not valid JavaScript identifiers (e.g., containing spaces or special characters).
  ```javascript
  const value = obj['property name'];
  ```

- **Using Libraries:** Libraries such as Lodash provide utility functions, e.g., `_.get`, which can facilitate safe property access when dealing with deeply nested objects, potentially improving robustness over raw property access.
  
By analyzing the results and pros/cons, software engineers can make informed decisions based on performance requirements and code readability.

Related benchmarks:

desctructuring object keys vs access via dot (version: 1)

Comparing performance of: Destructuring vs Dot notation

Created: one year ago by: Registered User

Jump to the latest result

Destructuring

Dot notation

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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