Benchmark: Object destructuring performance

Tests:

Without destructuring
const array = new Array(3); for (let i = 0; i < 10000; i++) { const length = array.length; }
With destructuring
const array = new Array(3); for (let i = 0; i < 10000; i++) { const {length} = array; }
With destructuring and renaming
const array = new Array(3); for (let i = 0; i < 10000; i++) { const {length: property} = array; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Without destructuring
With destructuring
With destructuring and renaming

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 6 months ago)

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 26_0_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Brave/1 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 26 on iOS 26.0.1

View result in a separate tab

Test name	Executions per second
Without destructuring	415981.2 Ops/sec
With destructuring	415284.0 Ops/sec
With destructuring and renaming	415754.8 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 provided benchmark definition and test cases to understand what is being tested.

**Benchmark Definition**

The benchmark definition represents a JavaScript microbenchmark that measures the performance of object destructuring in different scenarios. The script preparation code and HTML preparation code are empty, indicating that these steps are not relevant to the specific task being measured.

**Test Cases**

There are three test cases:

1. **Without Destructuring**: This test case checks the performance of accessing an object's length property directly using `array.length`.
2. **With Destructuring**: This test case compares the performance of accessing an object's length property using destructuring syntax (`const {length} = array;`).
3. **With Destructuring and Renaming**: This test case extends the previous one by also renaming the accessed property to a custom name (`const {length: property} = array;`).

**Options Compared**

The benchmark compares the performance of three different approaches:

* Directly accessing the object's length property using `array.length`.
* Accessing an object's property using destructuring syntax (`{length}`).
* Accessing an object's property with renaming using destructuring syntax (`{length: property}`).

**Pros and Cons**

Here are some pros and cons of each approach:

1. **Directly accessing the object's length property`**:
	* Pros: Simple, straightforward way to access the property.
	* Cons: May not be as readable or maintainable, especially for larger objects.
2. **Accessing an object's property using destructuring syntax (`{length}`)**:
	* Pros: More concise and readable than directly accessing the property.
	* Cons: May introduce additional overhead due to the parsing of the destructuring expression.
3. **Accessing an object's property with renaming using destructuring syntax (`{length: property}`)**:
	* Pros: Combines the benefits of readability and performance by allowing for property renaming.
	* Cons: May add unnecessary complexity, especially if the renamed property is not actually used.

**Library Usage**

None of the test cases use any external libraries. The benchmark only relies on standard JavaScript features.

**Special JS Features or Syntax**

The test case using destructuring syntax (`{length}`) does not introduce any special features or syntax that are unique to modern JavaScript versions (e.g., ECMAScript 2015+). However, the use of destructuring syntax is a feature introduced in ECMAScript 2015.

**Alternatives**

If you were to reimplement this benchmark using different approaches, here are some alternatives:

1. Using a more efficient data structure, such as an array with a `length` property (e.g., `Array(3)` with a custom `length` property).
2. Using a library that provides optimized object access methods (e.g., `Object.keys()` or `Object.values()`).
3. Implementing a custom function to access the object's length property, potentially using inline caching or memoization.

Keep in mind that these alternatives would likely introduce additional complexity and may not provide significant performance benefits over the original benchmark.

Related benchmarks:

Object destructuring performance (version: 0)

Comparing performance of: Without destructuring vs With destructuring vs With destructuring and renaming

Created: 3 years ago by: Registered User

Jump to the latest result

Without destructuring

With destructuring

With destructuring and renaming

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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