Benchmark: className vs. setAttribute vs. classList parte dos

HTML Preparation code:

<div id="foo"></div>

Tests:

className
var element = document.getElementById("foo"); var i = 1000; while (i--) { element.className += "bar"; }
classList
var element = document.getElementById("foo"); var i = 1000; while (i--) { element.classList.add("bar"); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
className
classList

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

I'd be happy to explain the benchmark and its various components.

**Benchmark Definition**

The benchmark is defined by a JSON object that contains several key pieces of information:

* `Name`: The name of the benchmark, which is "className vs. setAttribute vs. classList parte dos".
* `Description`: An empty string, indicating that no description is provided for this benchmark.
* `Script Preparation Code` and `Html Preparation Code`: These fields are empty, suggesting that the script and HTML code for the benchmark should be provided separately or through a separate file.

**Individual Test Cases**

The benchmark consists of two individual test cases:

1. **className**: This test case is defined by a string containing JavaScript code that:
	* Retrieves an element from the DOM using `document.getElementById("foo")`.
	* Initializes a variable `i` with a value of 1000.
	* Enters a while loop that iterates 1000 times, appending "bar" to the `className` property of the retrieved element in each iteration.
2. **classList**: This test case is defined by a string containing JavaScript code that:
	* Retrieves an element from the DOM using `document.getElementById("foo")`.
	* Initializes a variable `i` with a value of 1000.
	* Enters a while loop that iterates 1000 times, adding "bar" to the `classList` property of the retrieved element in each iteration.

**Comparison of Approaches**

The benchmark is comparing three approaches:

1. **className**: This approach appends elements to the `className` property of an element using string concatenation.
2. **classList**: This approach adds elements to the `classList` property of an element, which is a separate concept from `className`.

**Pros and Cons of Each Approach**

* **className**:
	+ Pros: Simple and widely supported across browsers.
	+ Cons: Can lead to slower performance due to string concatenation.
* **classList**: This approach is generally faster and more efficient than appending elements to `className`, as it uses a more optimized data structure.

**Library Used**

Neither of the test cases explicitly uses any additional libraries beyond the standard JavaScript DOM APIs. However, it's worth noting that modern browsers like Chrome 84 support various features and optimizations that may affect performance, such as WebAssembly or Just-In-Time (JIT) compilation.

**Special JS Features or Syntax**

There are no special JS features or syntax used in these test cases. Both approaches rely on standard JavaScript semantics and DOM APIs.

**Alternative Approaches**

If you wanted to run a similar benchmark, here are some alternative approaches:

1. Use `style.add()` instead of `className` or `classList`. This method is available in modern browsers and can provide better performance.
2. Use CSS classes instead of JavaScript string manipulation. This approach can be faster and more efficient, especially for larger datasets.
3. Consider using benchmarking libraries like Benchmark.js or Microbenchmark.js to simplify the process of writing and running benchmarks.

Keep in mind that these alternative approaches may require adjustments to your code and testing environment to ensure accurate results.

Related benchmarks:

className vs. setAttribute vs. classList parte dos (version: 0)

Comparing performance of: className vs classList

Created: 5 years ago by: Guest

Jump to the latest result

className

classList

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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