Let's dive into the world of JavaScript microbenchmarks.

What is being tested?

MeasureThat.net is testing four different ways to retrieve elements by class name in HTML documents:

1. Using jQuery ($('.even'))
2. Using querySelectorAll (a native browser API, not part of jQuery)
3. Using getElementsByClassName
4. Using jQuery with an ID selector ($('#theList .even'))

These methods are tested on different browsers and devices to determine which one is the fastest.

Options compared

The four options being compared are:

1. jQuery: A popular JavaScript library for DOM manipulation.
2. querySelectorAll: A native browser API for querying the document tree.
3. getElementsByClassName: Another native browser API for retrieving elements by class name.
4. jQuery with ID selector: Using jQuery's # selector to target an element and then using querySelectorAll on that element.

Pros and cons of each approach

Here are some pros and cons of each approach:

1. jQuery:
   • Pros: Easy to use, widely supported, and fast.
   • Cons: Adds extra overhead due to its library size, and can lead to slower performance if not optimized correctly.
2. querySelectorAll:
   • Pros: Fast, lightweight, and native to browsers.
   • Cons: Requires more effort to write correct selectors, as it's not as intuitive as jQuery's syntax.
3. getElementsByClassName:
   • Pros: Simple to use and fast, but only works with className attribute.
   • Cons: Limited by the browser's implementation of this API, which may vary across versions and platforms.
4. jQuery with ID selector:
   • Pros: Combines the benefits of jQuery's ease of use with the speed of querySelectorAll.
   • Cons: Can add unnecessary overhead due to the extra function call.

Browser-specific observations

From the benchmark results, we can observe that:

1. getElementsByClassName is generally faster than jQuery and querySelectorAll (with ID selector) for the .even class.
2. querySelectorAll with an attribute selector ([class="even"]) is faster than jQuery for the .even class.
3. The results are consistent across different browsers, which suggests that the performance differences are not due to browser-specific implementations.

In conclusion, the choice of method depends on your specific use case and priorities:

• Use getElementsByClassName if you need a lightweight solution with fast performance.
• Use querySelectorAll (with attribute selectors) for optimal performance and flexibility.
• Consider using jQuery if you value ease of use and are willing to accept some overhead.

Keep in mind that this benchmark is specific to retrieving elements by class name, and results may vary depending on your specific requirements.