Benchmark: [#1] Spread vs Array.filter.call

Tests:

Spread
const elementCount = [...document.querySelectorAll('*')].filter(node => node.nodeType === node.ELEMENT_NODE);
Array.prototype case
const elementCount = Array.prototype.filter.call(document.querySelectorAll('*'), node => node.nodeType === node.ELEMENT_NODE);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Spread
Array.prototype case

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:147.0) Gecko/20100101 Firefox/147.0

Browser/OS: Firefox 147 on Windows

View result in a separate tab

Test name	Executions per second
Spread	636727.9 Ops/sec
Array.prototype case	657887.0 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 benchmarking setup.

**Benchmark Purpose**

The test measures the performance difference between two approaches: using the spread operator (`...`) to create an array from `document.querySelectorAll('*')`, and using the `Array.prototype.filter.call()` method to filter elements.

**Options Compared**

There are two main options being compared:

1. **Spread Operator**: This approach creates a new array by spreading the NodeList returned by `document.querySelectorAll('*')`. The spread operator is a shorthand way of creating a new array from an iterable.
2. **Array.prototype.filter.call()**: This approach uses the `filter()` method on the Array prototype, passing a callback function to filter elements based on their node type.

**Pros and Cons**

- **Spread Operator**:
  * Pros: More concise and readable code.
  * Cons: Creates a new array, which can be memory-intensive for large datasets. Also, it's not explicitly typed, making it less predictable.
- **Array.prototype.filter.call()**:
  * Pros: Can be more efficient in terms of memory usage, as it doesn't create a new array.
  * Cons: Requires using the `call()` method to pass the callback function, which can make the code less readable.

**Library and Special JS Features**

There is no explicit library mentioned in the benchmark definition or test cases. However, `document.querySelectorAll('*')` returns an HTML NodeList, which is a proprietary feature of the Web API for working with HTML documents.

**Other Alternatives**

If you need to filter elements from a large dataset, other alternatives could be:

* Using `Array.from()` instead of the spread operator.
* Using a library like Lodash, which provides a `filterByType` function that can handle node types and reduce memory usage.
* Using a different data structure, such as a Set or Map, if the filtering logic is complex.

**Benchmark Preparation Code**

The benchmark preparation code is empty in this case. In a typical benchmarking setup, you would create a scenario where the code to be measured is executed multiple times to gather performance metrics.

The individual test cases are well-defined and provide clear instructions for each approach being tested.

Related benchmarks:

[#1] Spread vs Array.filter.call (version: 2)

Comparing performance of: Spread vs Array.prototype case

Created: 3 years ago by: Registered User

Jump to the latest result

Spread

Array.prototype case

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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