Benchmark: Selector Order - MeasureThat.net

HTML Preparation code:

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Tests:

Attribute first
document.querySelectorAll('[style].cic_super-hidden');
Class first
document.querySelectorAll('.cic_super-hidden[style]');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Attribute first
Class first

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark definition and test cases to understand what is being tested, compared, and their pros/cons.

**Benchmark Definition JSON**

The provided JSON represents a JavaScript microbenchmark that tests the speed of ordering attribute and class selectors using `document.querySelectorAll`. The benchmark allows users to create and run custom benchmarks on their own JavaScript code.

**Script Preparation Code and HTML Preparation Code**

There is no script preparation code provided, which means that the user will need to write their own code to test in the benchmark. However, the HTML preparation code generates a set of elements with various styles applied to them, including classes (`test`) and inline styles (`style`).

**Test Cases**

The benchmark includes two test cases:

1. **Attribute first**: The `document.querySelectorAll('[style].cic_super-hidden')` query selects elements where `style` is an attribute and the value is `.cic_super-hidden`.
2. **Class first**: The `document.querySelectorAll('.cic_super-hidden[style]')` query selects elements where `.cic_super-hidden` is a class and there is a `style` attribute.

**What is being compared?**

These two test cases compare the performance of using attribute selectors (`[style]`) versus class selectors (`.[class]`) in JavaScript. Specifically, they are comparing:

* The order in which the selector is applied: `attribute first` vs `class first`
* The performance impact of using these different approaches on the DOM

**Pros/Cons of each approach**

1. **Attribute first ( `[style].cic_super-hidden` )**
	* Pros:
		+ May be faster since attribute selectors are often more efficient than class selectors
		+ Can be useful for older browsers that don't support class selectors
	* Cons:
		+ Can be less readable and maintainable due to the use of `style` as an attribute
2. **Class first ( `.cic_super-hidden[style]` )**
	* Pros:
		+ More readable and maintainable since classes are a standardized way to group elements
		+ Often faster than attribute selectors for modern browsers
	* Cons:
		+ May be slower in older browsers that don't support class selectors

**Library and special JS features**

There is no explicit library mentioned, but the benchmark uses the `document.querySelectorAll` method, which is a standard JavaScript API. However, the use of `[style]` attribute syntax might not be supported in all JavaScript environments (e.g., older browsers).

**Other alternatives**

If you need to test other approaches or variants of these tests, you could consider using alternative methods such as:

* Using `Element.prototype.querySelector` instead of `document.querySelectorAll`
* Adding additional styles or classes to the elements
* Changing the order of selectors in the query string (e.g., `.cic_super-hidden [style]`)
* Using a different element selector syntax (e.g., `>` instead of `[style]`)

Latest run results:

Run details: (Test run date: 7 years ago)

User agent: Mozilla/5.0 (X11; Fedora; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36

Browser/OS: Chrome 59 on Fedora

View result in a separate tab

Test name	Executions per second
Attribute first	644.0 Ops/sec
Class first	647.2 Ops/sec

Related benchmarks:

Selector Order (version: 3)

Test speed of ordering attribute and class selectors

Comparing performance of: Attribute first vs Class first

Created: 7 years ago by: Registered User

Jump to the latest result

Attribute first

Class first

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):