Benchmark: test if id selector is faster

HTML Preparation code:

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
<div id="maincontainer">
                             <div class="container">
    <div class="row">
        <div class="col-md-12">
             <h1>Long service leave</h1>
        </div>
    </div>
</div>
<article class="content-page">
	<div class="container">
		<div class="row">
		    
			<div class="col-md-8 articleContent">
				
<div id="content_container_540237">
<h2 id="What-is-long-service-leave">What is long service leave</h2><h2 id="Entitlement-(not-mining-employees)">Entitlement (not mining employees)</h2><h2 id="Continuous-employment">Continuous employment</h2><h2 id="Cashing-in-long-service-leave">Cashing-in long service leave</h2><h2 id="Payment-for-long-service-leave">Payment for long service leave</h2><h2 id="Casual-and-part-time-employees">Casual and part-time employees</h2>
</div>

				<span class="updated">Updated:  13th September 2019</span>
				                		
        		    			</div>
			
			<div class="col-md-4 rightHandMenu">
        	    <div class="pagewidget">
        	      	<div class="pagewidget__controls">
                		<button class="pagewidget__favourite" id="item_540235">
                		    <i class="far fa-heart"></i>
                		    <span>Add favourite</span></button>
                		 
                		
                		    <i class="fas fa-heart"></i>
                		    <span>1</span></a>
                		 
                		 <button class="pagewidget__print" onclick="window.print()">
                		    <i class="fas fa-print"></i>
                		    <span>Print<span>
                		 </span></span></button>
                	</div>
            		<div class="link-list related-links" id="onThisPage">
            			<h2 class="pagewidget__heading">On this page</h2>
            			<ul></ul>
            		</div>
			    </div>
		     </div>
		     
	    </div>
    </div>	
</article>

              </div>

Script Preparation code:

    var list = $('#onThisPage ul');

    $(".articleContent h2").each(function() {
      //  $(this).prepend('<a id="' + $(this).text().replace(/ /g,'-') + '"></a>');
        $(this).attr('id', $(this).text().replace(/ /g,'-'));
        $(list).append('<li><a href="#' + $(this).text().replace(/ /g,'-') + '">' +  $(this).text() + '</a></li>');
        
    });

Tests:

c1
$("#maincontainer .articleContent h2").each(function() { $(this).attr('id', $(this).text().replace(/ /g,'-')); $(list).append('<li><a href="#' + $(this).text().replace(/ /g,'-') + '">' + $(this).text() + '</a></li>'); });
c2
$("#maincontainer h2").each(function() { $(this).attr('id', $(this).text().replace(/ /g,'-')); $(list).append('<li><a href="#' + $(this).text().replace(/ /g,'-') + '">' + $(this).text() + '</a></li>'); });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
c1
c2

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON data and explain what's being tested, compared, and discussed.

**Benchmark Definition**

The benchmark is designed to compare the performance of two approaches:

1. `#maincontainer .articleContent h2`: This approach targets elements with both an ID selector (`#`) and a CSS class selector (`articleContent`).
2. `#maincontainer h2`: This approach targets only elements with an ID selector (`#`) but no additional CSS class selectors.

**Script Preparation Code**

The script preparation code is used to set up the environment for the benchmark. It:

* Retrieves all elements with the ID `onThisPage` using jQuery.
* Iterates over each element in `.articleContent h2` and:
	+ Replaces spaces in the text with dashes (`-`) to create a unique ID.
	+ Appends a new list item with an anchor tag containing the modified text.

**Html Preparation Code**

The HTML preparation code includes the necessary libraries (jQuery) and HTML structure for the benchmark. It sets up a container with multiple columns, each containing elements that will be targeted by the script preparation code.

**Individual Test Cases**

There are two individual test cases:

1. `c1`: Targets elements with both an ID selector (`#`) and a CSS class selector (`articleContent h2`).
2. `c2`: Targets only elements with an ID selector (`#maincontainer h2`).

**Comparison of Approaches**

The benchmark compares the performance of these two approaches:

* **Approach 1: `#maincontainer .articleContent h2`**
	+ Pros:
		- More specific targeting, which can lead to faster execution.
		- Less chance of matching other elements accidentally.
	+ Cons:
		- May require more processing power due to the additional CSS class selector.
* **Approach 2: `#maincontainer h2`**
	+ Pros:
		- Simpler and faster targeting, as it only requires an ID selector.
		- Less processing power required.
	+ Cons:
		- May match other elements accidentally, leading to slower execution.

**Library: jQuery**

The benchmark uses jQuery for its DOM manipulation and event handling. Specifically, the script preparation code uses `$(this)` and `.append()` methods from jQuery.

**Other Considerations**

* The benchmark uses a real-world HTML structure and content to make the results more relevant.
* The test cases are designed to simulate common web development scenarios where ID selectors are used.

**Alternatives**

If you're looking for alternative approaches, consider:

* Using CSS classes instead of IDs for targeting elements (e.g., `.articleContent h2`).
* Leveraging modern JavaScript features like `document.querySelectorAll()` or `Element.matches()` for more efficient and flexible DOM querying.
* Experimenting with different optimization techniques, such as caching or memoization, to improve performance.

Related benchmarks:

test if id selector is faster (version: 0)

kekit

Comparing performance of: c1 vs c2

Created: 6 years ago by: Guest

Jump to the latest result

c1

c2

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):