Benchmark: long vs short classlist contains

HTML Preparation code:

<div id="foo" class="bar bazbazbazbazbaz"></div>

Script Preparation code:

var test_element = document.getElementById("foo");

Tests:

long
test_element.classList.contains("bazbazbazbazbaz");
short
test_element.classList.contains("bar");

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
long
short

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's break down the provided benchmark and explain what is being tested, compared, and the pros/cons of different approaches.

**Benchmark Overview**

The benchmark measures the performance difference between using short class names versus long class names in CSS selectors on an HTML element. The test creates a simple HTML page with a div element containing multiple classes (bazbazbazbazbaz), and then executes two benchmarks:

1. `test_element.classList.contains("bazbazbazbazbaz");`: This benchmark checks if the given class is present in the element's class list using the `contains` method.
2. `test_element.classList.contains("bar");`: This benchmark checks if the given short class name ("bar") is present in the element's class list.

**Library Used**

The benchmark uses the `classList` API, which is a part of the DOM (Document Object Model) specification and is supported by most modern browsers. The `classList` property returns a `DOMTokenList` object, which represents the classes applied to an element.

In this case, the library used is not explicitly mentioned in the benchmark definition JSON. However, it's essential to note that the `classList` API relies on CSS classes being defined, and the browser must be able to parse and apply those styles.

**Special JavaScript Feature/Syntax**

There are no special features or syntaxes involved in this benchmark.

**Comparison of Approaches**

The two benchmarks compare the performance of using short class names versus long class names. The "short" benchmark uses a shorter class name ("bar"), while the "long" benchmark uses a longer class name ("bazbazbazbazbaz").

Pros and Cons:

* **Short Class Names (e.g., "bar")**:
	+ Pros: Typically faster, as shorter strings are less computationally expensive to compare.
	+ Cons: May not cover all cases, as some classes might be longer.
* **Long Class Names (e.g., "bazbazbazbazbaz")**:
	+ Pros: Covers more cases, as longer classes are more likely to be used.
	+ Cons: Typically slower, due to the increased computational cost of comparing longer strings.

**Considerations**

When writing benchmarks like this one, it's essential to consider the following:

* **Real-world usage**: Are these class names commonly used in real-world web development?
* **Browser support**: Will the browser being tested support the `classList` API and CSS classes?
* **Optimization**: Can optimizations be applied to reduce the performance difference between short and long class names?

**Other Alternatives**

If you wanted to create a similar benchmark, you could explore other approaches:

1. Measure the performance of using different comparison methods, such as:
	+ `indexOf()` or `indexOf() + 1`
	+ Regular expressions
	+ CSS selectors with `^` and `$` anchors
2. Create benchmarks for different use cases, such as:
	+ Nested class names (e.g., ".foo .bar baz")
	+ Class lists with multiple values (e.g., "foo bar baz")

By exploring these alternatives, you can create a more comprehensive set of benchmarks that better reflects real-world web development scenarios.

Related benchmarks:

long vs short classlist contains (version: 0)

Comparing performance of: long vs short

Created: 3 years ago by: Guest

Jump to the latest result

long

short

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):