Benchmark: Class vs Attribute selector modern

HTML Preparation code:

<input type="text" class="search" data-search-input/>
<div class="results" data-results>
  <div class="element" data-result-element>Hello</div>
  <div class="element" data-result-element>World</div>
  <div class="element" data-result-element>Everyone</div>
</div>

Tests:

Class selector
let list = document.querySelector('.results'); let list_item = document.querySelector('.element'); let input = document.querySelector('.search');
Attribute selector
let list = document.querySelector('[class="results"]'); let list_item = document.querySelector('[class="element"]'); let input = document.querySelector('[class="search"]');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Class selector
Attribute selector

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.36

Browser/OS: Chrome 146 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Class selector	11198585.0 Ops/sec
Attribute selector	4492854.0 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 JSON data and explain what's being tested, compared, and their pros/cons.

**Benchmark Definition**

The benchmark definition is a set of instructions that defines how to prepare the environment for testing. In this case, it includes:

* A script preparation code: This section is empty, which means no custom JavaScript code needs to be executed before running the tests.
* An HTML preparation code: This section defines an HTML page with three elements: `input` (a text input), `list` (an element with class `results`), and multiple `element` elements (each with class `element`). The presence of these elements is expected during testing.

**Individual Test Cases**

There are two test cases defined:

1. **Class selector**
	* Benchmark Definition: `let list = document.querySelector('.results'); let list_item = document.querySelector('.element'); let input = document.querySelector('.search');`
	* Description: This test case uses the `querySelector` method to select elements based on their class names.
2. **Attribute selector**
	* Benchmark Definition: `let list = document.querySelector('[class="results"]'); let list_item = document.querySelector('[class="element"]'); let input = document.querySelector('[class="search"]');`
	* Description: This test case uses the `querySelector` method with attribute selectors to select elements based on their class attributes.

**Comparison and Pros/Cons**

Both test cases use the `querySelector` method, which is a part of the Document Object Model (DOM). However, they differ in how they specify the selector:

* **Class selector**: Uses dot notation (`.`) followed by the class name. This approach is more readable and concise.
	+ Pros: Easier to read and maintain, especially for smaller classes or attributes.
	+ Cons: May be slower due to the DOM query optimization algorithm (e.g., using caching).
* **Attribute selector**: Uses square brackets `[]` followed by the attribute name and value. This approach is more flexible but also more verbose.
	+ Pros: Can match elements based on any attribute, regardless of its position or order in the HTML document.
	+ Cons: May be slower due to the DOM query optimization algorithm and can lead to more complex selectors.

**Library**

There is no explicit library mentioned in the provided data. However, the `querySelector` method is part of the W3C standard and is widely supported by most modern browsers.

**Special JS Features/Syntax**

None are explicitly mentioned in this specific benchmark definition. However, note that if you were to create a new test case or benchmark using these methods, you might use more advanced techniques like:

* Using `getAttribute` and `setAttribute` instead of attribute selectors for more fine-grained control.
* Utilizing CSS selectors, such as `querySelectorAll`, for more complex selection logic.
* Leveraging the `DOMQuerySelectorOptions` interface for custom query optimizations.

**Other Alternatives**

If you wanted to test different approaches or libraries, consider exploring:

* Other DOM query methods like `getElementsByClassName` or `getElementById`.
* CSS selectors for more precise and flexible element selection (e.g., using `querySelectorAll`).
* Browser-specific APIs like `window.getComputedStyle` for CSS styles or attribute access.
* Library-based solutions like jQuery or other utility libraries that provide a more convenient, high-level API for DOM manipulation.

Keep in mind that the choice of approach depends on your specific requirements and performance considerations.

Related benchmarks:

Class vs Attribute selector modern (version: 0)

Comparing performance of: Class selector vs Attribute selector

Created: 3 years ago by: Guest

Jump to the latest result

Class selector

Attribute selector

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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