Benchmark: jquery $(querySelectorAll) vs $(".class")

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/jquery/3.7.1/jquery.js'></script>
<div>
    <ul id="menu">
        <li class="menu-item">
        </li>
        <li class="menu-item">
        </li>
        <li class="menu-item">
        </li>
        <li class="menu-item">
        </li>

    </ul>
</div>

Script Preparation code:

const elem = $(".menu-item");

Tests:

querySelectorAll
if ($(document.querySelectorAll(".test")).css("opacity") == "0.2") $(document.querySelectorAll(".test")).css("opacity", "1"); else $(document.querySelectorAll(".test")).css("opacity", "0.2");
$(".class")
if ($(".test").css("opacity") == "0.2") $(".test").css("opacity", "1"); else $(".test").css("opacity", "0.2");
$(elem)
if ($(elem).css("opacity") == "0.2") $(elem).css("opacity", "1"); else $(elem).css("opacity", "0.2");

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
querySelectorAll
$(".class")
$(elem)

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 13 days ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.0 Safari/537.36 Edg/135.0.0.0

Browser/OS: Chrome 135 on Windows

View result in a separate tab

Test name	Executions per second
querySelectorAll	324032.4 Ops/sec
$(".class")	232215.9 Ops/sec
$(elem)	31191.8 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated 12 days ago):

LLMs can make mistakes. Check important info.

The benchmark illustrated in the JSON primarily compares three different methods of selecting DOM elements and manipulating their CSS properties using jQuery, a widely-used JavaScript library for simplifying HTML document traversing, event handling, and animation. The specific tests being compared are:

1. **`querySelectorAll` as a jQuery selector**:
   - **Test Name**: `querySelectorAll`
   - **Benchmark Definition**: `if ($(document.querySelectorAll(".test")).css("opacity") == "0.2") $(document.querySelectorAll(".test")).css("opacity", "1"); else $(document.querySelectorAll(".test")).css("opacity", "0.2");`
   - **Purpose**: This test utilizes the native `document.querySelectorAll` method to find elements by class and then applies a jQuery method to manipulate the CSS opacity property.

2. **Selecting elements by jQuery class selector**:
   - **Test Name**: `$(".class")`
   - **Benchmark Definition**: `if ($(".test").css("opacity") == "0.2") $(".test").css("opacity", "1"); else $(".test").css("opacity", "0.2");`
   - **Purpose**: This test directly uses jQuery's built-in class selector to select elements with the class "test" and again manipulates their CSS properties.

3. **Using a pre-selected jQuery element reference**:
   - **Test Name**: `$(elem)`
   - **Benchmark Definition**: `if ($(elem).css("opacity") == "0.2") $(elem).css("opacity", "1"); else $(elem).css("opacity", "0.2");`
   - **Purpose**: In this case, a previously cached or pre-selected jQuery object `elem` (which contains the jQuery selection of elements with class "menu-item") is used to manipulate the opacity.

### Pros and Cons:

1. **Using `querySelectorAll`**:
   - **Pros**:
     - Leverages native browser functionality, which is typically faster for selecting elements.
   - **Cons**:
     - Requires wrapping the result in jQuery, which could introduce overhead.
     - May lead to more complex or verbose code.

2. **Using jQuery class selector**:
   - **Pros**:
     - Simplifies code with a cleaner syntax, easier for those familiar with jQuery.
     - Better integration with jQuery's chaining and utilities.
   - **Cons**:
     - Slightly less performant than native selectors due to jQuery's internal processing.

3. **Using cached jQuery reference**:
   - **Pros**:
     - Offers the best performance for several operations on the same set of elements since it avoids repeated selection.
   - **Cons**:
     - Introduces complexity in maintaining state if the DOM changes dynamically and if the references are not updated accordingly.

### Alternative Approaches:
In addition to the methods tested, developers can also consider:

- **Native `document.querySelector` or `document.getElementsByClassName`**: For similar performance as `querySelectorAll` without the jQuery overhead.
- **Vanilla JavaScript for DOM Manipulation**: Using native methods and properties like `element.style.opacity` can further improve performance, eliminating the need for jQuery entirely in modern web applications given that native features are well-optimized in browsers.

The benchmark results demonstrate performance variances between the approaches, showing that using `querySelectorAll` (324032.44 Executions/Second) is the most efficient, followed by jQuery's class selector (232215.92 Executions/Second), and ultimately the pre-selected jQuery reference (31191.83 Executions/Second).

### Other Considerations:
When deciding which approach to use, developers should take into account:

- The overall size and complexity of the JavaScript application.
- The performance requirements and visitor experience.
- The necessary browser support, especially for older versions, where jQuery may offer better compatibility guarantees.
- Modern applications are increasingly moving towards native JavaScript solutions due to advancements in the language and library capabilities, particularly with the recent enhancements in browser performance and capabilities.

Related benchmarks:

jquery $(querySelectorAll) vs $(".class") (version: 1)

Comparing performance of: querySelectorAll vs $(".class") vs $(elem)

Created: 13 days ago by: Guest

Jump to the latest result

querySelectorAll

$(".class")

$(elem)

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated 12 days ago):