Benchmark: jQuery `tag.class` vs `.class`

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js'></script>
<ul>
  <li class="c">Foo</li>
  <li class="c">Bar</li>
  <li class="c">Baz</li>
</ul>

Tests:

tag.class
$('li.c');
.class
$('.c');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
tag.class
.class

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.

I'd be happy to explain what's being tested in the provided benchmark.

**What is tested:**

The benchmark measures the performance difference between two ways of selecting elements with a class using jQuery:

1. **`tag.class`**: This method uses the `class` attribute of an HTML element to select all elements that have both classes "c". In other words, it looks for elements like `<li class="c">Foo</li>`.
2. **`.class`**: This method uses a CSS selector syntax with a dot (`.`) instead of a hyphen (`-`) to select elements with the class "c".

**Options compared:**

The benchmark compares the execution speed of these two approaches:

* **`tag.class`**
* **`.class`**

**Pros and cons of each approach:**

1. **`tag.class`**:
	* Pros:
		+ Works in older browsers that don't support CSS selectors.
		+ May be faster due to the simplicity of the selector syntax.
	* Cons:
		+ Not as readable or maintainable, especially for complex class selections.
2. **`.class`**:
	* Pros:
		+ More readable and maintainable than `tag.class`.
		+ Works in modern browsers that support CSS selectors.
	* Cons:
		+ May be slower due to the complexity of the selector syntax.

**Library:**

The benchmark uses jQuery, a popular JavaScript library for DOM manipulation. In this case, it's used to select elements with a specific class.

**Special JS feature or syntax:**

This benchmark doesn't use any special JavaScript features or syntax. However, it does rely on the fact that modern browsers support CSS selectors in their DOM manipulation APIs.

**Other alternatives:**

If you want to compare the performance of these two approaches without using jQuery, you can also consider using a plain JavaScript implementation with `document.querySelectorAll` and `document.getElementsByClassName`. The benchmark might look something like this:

```json
{
    "Name": "jQuery `tag.class` vs `.class`",
    "Description": null,
    "Script Preparation Code": null,
    "Html Preparation Code": "<html><body><ul><li class=\"c\">Foo</li><li class=\"c\">Bar</li><li class=\"c\">Baz</li></ul></body></html>"
}
```

Individual test cases:

```json
[
    {
        "Benchmark Definition": "document.querySelector('li.c');",
        "Test Name": "tag.class"
    },
    {
        "Benchmark Definition": "document.getElementsByClassName('c')[0];",
        "Test Name": ".class"
    }
]
```

Keep in mind that this plain JavaScript implementation would require additional setup, such as creating a function to parse CSS selectors and generate the corresponding jQuery-like selector string.

Related benchmarks:

jQuery `tag.class` vs `.class` (version: 0)

Comparing performance of: tag.class vs .class

Created: 5 years ago by: Guest

Jump to the latest result

tag.class

.class

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):