Benchmark: Class Selector vs ID Selector vs Name aatr selector

HTML Preparation code:

<div class="hello" name="helloName" id="hello" data-hello="some long long long long value" data-test="hello-and-bye">Hello</div>	>Hello</div>

Tests:

class
document.querySelector('.hello');
id
document.querySelector('#hello');
name
document.getElementsByName('helloName')[0];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
class
id
name

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**What is tested?**

The provided JSON represents a benchmark that tests three different approaches to select an HTML element using various selectors:

1. **Class selector**: `document.querySelector('.hello');`
2. **ID selector**: `document.querySelector('#hello');`
3. **Name attribute selector**: `document.getElementsByName('helloName')[0];`

These test cases aim to measure the performance differences between these three approaches.

**Options compared**

Here are the options being compared:

1. **Class selector**: Uses the `.hello` class to select the element.
2. **ID selector**: Uses the `#hello` ID to select the element.
3. **Name attribute selector**: Uses the `name` attribute with value `'helloName'` to select the element.

**Pros and cons of each approach**

1. **Class selector**:
	* Pros: Efficient use of class names, easy to implement.
	* Cons: May not work if multiple elements have the same class name.
2. **ID selector**:
	* Pros: Unique ID per element, fast lookup.
	* Cons: May not be suitable for all scenarios (e.g., if IDs are generated dynamically).
3. **Name attribute selector**:
	* Pros: Simple and easy to use, but may lead to slower performance due to the `getElementsByName` method's implementation.
	* Cons: Not as efficient as class or ID selectors, potential security issues with user-inputted values.

**Library usage**

The test case using `document.getElementsByName('helloName')[0];` uses the `getElementsByName` method from the DOM API. This method is intended to retrieve all elements whose name attribute matches the specified value. However, this implementation can lead to performance issues due to its slow and resource-intensive nature.

**Special JS feature or syntax**

There are no special JavaScript features or syntaxes being tested in these benchmark cases. The test focuses solely on comparing different selector approaches.

**Other alternatives**

If you're looking for alternative methods to select HTML elements, consider the following:

1. **QuerySelectorAll**: An extension of `querySelector` that allows selecting multiple elements using a comma-separated list.
2. **CSS Selectors**: You can use CSS selectors like `:nth-child`, `:first-child`, or `:last-child` to filter elements based on their position or attributes.
3. **JQuery**: A popular JavaScript library that provides an `$('selector')` method for selecting elements.

Keep in mind that the choice of selector depends on your specific use case and performance requirements.

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/115.0.0.0 Safari/537.36

Browser/OS: Chrome 115 on Windows

View result in a separate tab

Test name	Executions per second
class	4646819.0 Ops/sec
id	3490534.0 Ops/sec
name	5100866.5 Ops/sec

Related benchmarks:

Class Selector vs ID Selector vs Name aatr selector (version: 0)

Comparing performance of: class vs id vs name

Created: one year ago by: Guest

Jump to the latest result

class

id

name

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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