<div id="footer-info" class="clearfix test"></div>
var el = document.getElementById('footer-info');
var el = document.getElementsByClassName('test');
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
getElementById | |
getElementsByClassName |
Test name | Executions per second |
---|---|
getElementById | 3025370.2 Ops/sec |
getElementsByClassName | 2229492.5 Ops/sec |
Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.
What is tested?
The provided benchmark tests the performance of two different methods to retrieve HTML elements: getElementById
and getElementsByClassName
. These are fundamental DOM manipulation techniques used extensively in web development.
Options compared
We have two test cases:
document.getElementById('footer-info')
: This method retrieves an element by its ID, which is a unique identifier for the element.document.getElementsByClassName('test')
: This method retrieves all elements with a specific class name.Pros and Cons of each approach
getElementById
getElementsByClassName
Library and its purpose
In neither of the provided benchmark test cases are any libraries explicitly mentioned. The document
object, which is part of the browser's DOM API, is used for both tests. However, if you were to use a library like jQuery or another framework that extends the DOM API, it might affect performance.
Special JS feature or syntax
There are no special features or syntaxes mentioned in these test cases. They focus on the basic functionality of getElementById
and getElementsByClassName
.
Now, let's take a look at some alternative approaches to consider:
document.getElementById
or getElementsByClassName
, you can use CSS selectors like #footer-info
or .test
. This approach is often faster than the above methods since it relies on the browser's rendering engine, which is optimized for performance.querySelector
and querySelectorAll
methods as a part of their DOM API. These methods provide similar functionality to document.getElementById
and getElementsByClassName
, but are often faster due to improved caching and optimizations.To write your own benchmark on MeasureThat.net, you would need to create a new benchmark definition with the same structure as provided in your example, including HTML preparation code and individual test cases.