Benchmark: className vs. classList

Script Preparation code:

var element = document.createElement('div');
$element = $(element);

Tests:

className =
element.className = ''; element.className = 'bar';
className +=
element.className = ''; element.className += ' bar';
classList
element.className = ''; element.classList.add('bar');
addClass
element.className = ''; $element.addClass('bar');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
className =
className +=
classList
addClass

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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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 is tested, the pros and cons of different approaches, and other considerations.

**What is being tested:**

The benchmark compares four ways to add or update the `className` property of an HTML element:

1. Using the `=` operator (`element.className = 'bar'`)
2. Using the `+=` operator (`element.className += ' bar'`)
3. Using the `classList.add()` method (`element.classList.add('bar')`)
4. Using a jQuery wrapper (`$element.addClass('bar')`)

The benchmark tests the performance of each approach, and the results are displayed on the MeasureThat.net website.

**Options compared:**

1. **Simple assignment (`element.className = 'bar'`)**:
	* Pros: Simple and widely supported, easy to understand.
	* Cons: May not be optimized by modern browsers, can lead to unnecessary DOM modifications.
2. **Chainable assignment (`element.className += ' bar'`)**:
	* Pros: Can be more efficient in some cases, as it avoids creating a temporary string.
	* Cons: May lead to slower performance due to the creation of a new string, and is less readable than simple assignment.
3. **classList.add() method**:
	* Pros: Optimized by modern browsers for added performance, provides a way to manage class lists more efficiently.
	* Cons: Requires knowledge of the `classList` property, which may not be familiar to all developers.
4. **jQuery wrapper (`$element.addClass('bar')`)**:
	* Pros: Can provide additional functionality, such as handling multiple classes or other DOM manipulations.
	* Cons: Adds overhead due to jQuery's complexity and may not be necessary for simple class management.

**Other considerations:**

* The benchmark uses a relatively small string value ('bar'), which might lead to slower performance compared to larger strings or more complex class names.
* The use of the `$` symbol suggests that the benchmark is designed to run in a browser environment where jQuery is available, but it's not necessary for vanilla JavaScript development.

**Library usage:**

The benchmark uses the `classList` property, which is a built-in feature in modern browsers. However, older browsers may not support this property, and alternative solutions like using strings or other libraries might be needed to ensure compatibility.

If you're interested in exploring alternatives, here are some options:

* For simple class management, consider using vanilla JavaScript functions like `element.className` and `element.classList.add()` instead of the jQuery wrapper.
* For more complex class management or additional functionality, explore libraries like jQuery UI, ClassList.js, or other specialized tools.

Keep in mind that each approach has its own trade-offs, and the choice ultimately depends on your specific use case, performance requirements, and personal preference.

Related benchmarks:

className vs. classList (version: 3)

Fork from https://measurethat.net/Benchmarks/Show/54/0/classname-vs-setattribute-vs-classlist

Comparing performance of: className = vs className += vs classList vs addClass

Created: 8 years ago by: Registered User

Jump to the latest result

className =

className +=

classList

addClass

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):