Benchmark: DataAttribute vs Class Selector on body

HTML Preparation code:

<body class="hello" data-hello>Hello</div>

Tests:

Class
document.body.classList.contains('hello')
data attribute
document.body.dataset.hello;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Class
data attribute

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36

Browser/OS: Chrome 121 on Windows

View result in a separate tab

Test name	Executions per second
Class	2967007.5 Ops/sec
data attribute	2582077.5 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 and explain what's being tested.

**Benchmark Overview**

The benchmark is designed to compare the performance of two approaches: using the `classList.contains()` method on an HTML element (referred to as "Class") and accessing a data attribute using the `dataset` property (`data attribute`). The benchmark uses JavaScript microbenchmarks, which aim to isolate specific parts of code to measure their execution time.

**Options Compared**

Two options are being compared:

1. **Class**: This approach uses the `classList.contains()` method to check if an HTML element contains a specific class name.
2. **Data Attribute**: This approach accesses the value of a data attribute using the `dataset` property, specifically `data-hello`.

**Pros and Cons**

Here's a brief analysis of each approach:

* **Class**:
	+ Pros: This method is widely supported across browsers, including older versions that may not have implemented `dataset`.
	+ Cons: It requires multiple DOM queries to check for the presence of a class, which can lead to slower performance compared to accessing data attributes directly.
* **Data Attribute**:
	+ Pros: Accessing data attributes directly provides faster performance since it eliminates the need for DOM queries. This approach is also more readable and maintainable in modern web development.
	+ Cons: Not all browsers support `dataset` property, although most recent versions do.

**Library/Features Used**

The benchmark uses JavaScript features that are widely supported:

* `classList.contains()`: A built-in method of HTML elements to check for class names.
* `dataset`: A property of HTML elements that provides access to their attributes as key-value pairs.

**Special JS Feature/Syntax**

There's no special JavaScript feature or syntax used in this benchmark. The code is straightforward and uses standard DOM interactions.

**Other Alternatives**

If you wanted to optimize the performance further, you could consider:

* Using `getComputedStyle()` method to retrieve the computed style of an element instead of using `classList.contains()`.
* Accessing data attributes as properties (e.g., `document.body.hello`) for even faster access.
* Considering other methods like using `querySelectorAll()` or `getElementById()` if you need more complex DOM queries.

Keep in mind that the performance differences between these approaches can be minor and may not significantly impact your application's overall performance. The benchmark aims to provide a general idea of how different methods compare, allowing developers to make informed decisions about their code optimization strategies.

Related benchmarks:

DataAttribute vs Class Selector on body (version: 0)

Comparing performance of: Class vs data attribute

Created: 2 years ago by: Guest

Jump to the latest result

Class

data attribute

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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