Benchmark: Destructure array vs Array index

Tests:

Destructure array
const things = [{name: 'Alan', swearing: 'Mid'}, {name: 'Jason', swearing: 'High'}, {name: 'Stuart', swearing: 'Low'}] const [first] = things
Array index
const things = [{name: 'Alan', swearing: 'Mid'}, {name: 'Jason', swearing: 'High'}, {name: 'Stuart', swearing: 'Low'}] const first = things[0]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Destructure array
Array index

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/140.0.0.0 YaBrowser/25.10.0.0 Safari/537.36

Browser/OS: Yandex Browser 25 on Windows

View result in a separate tab

Test name	Executions per second
Destructure array	45199808.0 Ops/sec
Array index	62135588.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'd be happy to explain what's being tested in this benchmark.

**What is being tested?**

The provided benchmark compares the performance of two ways to access an element in an array: destructuring and using square bracket notation (array index).

**Destructuring vs Array Index**

In JavaScript, arrays can be used as objects, allowing you to access elements by name. This feature is called "object literal expressions" or "property access". In the benchmark, two test cases are run:

1. **Destructure array**: The `const [first] = things` syntax destructures the `things` array into an object with a single property `first`. This approach allows you to access elements by name, rather than using numerical indices.
2. **Array index**: The `const first = things[0]` syntax accesses the first element of the array using its numerical index.

**Options compared**

The benchmark compares two options:

1. **Destructuring**: Accessing elements by name using object literal expressions (e.g., `const [first] = things`)
2. **Array Index**: Accessing elements by their numerical indices (e.g., `const first = things[0]`)

**Pros and Cons of each approach**

* **Destructuring**:
	+ Pros: More readable code, allows for early returns and error handling.
	+ Cons: Can be slower than using array indices due to the overhead of object creation and property access.
* **Array Index**:
	+ Pros: Faster performance, as it uses a simple array lookup operation.
	+ Cons: Less readable code, requires numerical indexing which can lead to off-by-one errors.

**Library usage**

In this benchmark, there are no external libraries used. The test code is self-contained and only relies on the JavaScript standard library.

**Special JS features or syntax**

There are no special JavaScript features or syntaxes used in this benchmark. Both destructuring and array index approaches are basic JavaScript constructs.

**Other alternatives**

If you wanted to optimize performance, you could consider:

1. **Caching**: Precomputing and caching frequently accessed elements or arrays.
2. **Interpolation**: Using `let first = things[0];` instead of `[first] = things;`, which can be faster for small arrays.
3. **Native array methods**: Using native array methods like `Math.max()` or `Array.prototype.findIndex()` for more complex operations.

Keep in mind that these optimizations might come at the cost of readability and maintainability, so use them judiciously based on your specific use case.

Related benchmarks:

Destructure array vs Array index (version: 0)

Comparing performance of: Destructure array vs Array index

Created: 3 years ago by: Registered User

Jump to the latest result

Destructure array

Array index

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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