Benchmark: className vs. classList (comparing and adding)xxzczxccxzxcz

HTML Preparation code:

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

Tests:

className
var element = document.getElementById("foo"); var i = 1000; while (i--) { if(element.className.indexOf("test") > -1) { element.className = "bar"; }else { element.className = "test"; } }
classList
var element = document.getElementById("foo"); var i = 1000; while (i--) { if(element.classList.contains("test")) { element.classList.add("bar"); } else { element.classList.add("test"); } }

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.

Let's break down the benchmark definition and test cases to understand what is being tested.

**Benchmark Definition:**

The benchmark definition is a JSON object that provides information about the benchmark, including its name, description, script preparation code, HTML preparation code, and other details. In this case, the benchmark is comparing two approaches for adding or updating the class names of an HTML element:

1. Using `className` property directly.
2. Using `classList` property (introduced in ECMAScript 2015) to add or update classes.

**Test Cases:**

The test cases are individual benchmarks that measure the performance of each approach. There are two test cases:

1. **"className"`**: This benchmark measures the performance of using the `className` property directly to add or update the class names of an HTML element.
2. **"classList"`**: This benchmark measures the performance of using the `classList` property (introduced in ECMAScript 2015) to add or update classes.

**Options Compared:**

The two options being compared are:

1. Using `className` property directly.
2. Using `classList` property.

**Pros and Cons:**

* **Using `className` property directly:**
	+ Pros:
		- Widely supported in older browsers that don't support `classList`.
		- Can be more readable for simple cases.
	+ Cons:
		- Can lead to slower performance due to the need for string manipulation and searching.
		- May not be as efficient as using `classList` when dealing with multiple classes.
* **Using `classList` property:**
	+ Pros:
		- More efficient than using `className` directly, especially when dealing with multiple classes.
		- Can take advantage of browser optimizations for class manipulation.
	+ Cons:
		- Requires support for ECMAScript 2015 or later.
		- May be less readable for those not familiar with the `classList` property.

**Library:**

There is no explicit library mentioned in the benchmark definition, but it's likely that the HTML element being tested has a `classList` property (introduced in ECMAScript 2015). The `classList` property is part of the DOM API and provides an array-like interface for working with classes.

**Special JS Features or Syntax:**

There are no special JS features or syntax mentioned in the benchmark definition. However, it's worth noting that the `classList` property was introduced in ECMAScript 2015, which may be a limiting factor for browsers that don't support this feature.

**Other Alternatives:**

If you need to compare performance with other approaches, such as:

1. Using `setAttribute` or `setAttributeNS` to set class names.
2. Using CSS classes directly (e.g., `.test { ... }`) and accessing them via the DOM.
3. Using a library like jQuery or React for class manipulation.

These alternatives would require additional test cases and modifications to the benchmark definition.

Related benchmarks:

className vs. classList (comparing and adding)xxzczxccxzxcz (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):