Let's dive into the benchmark.

Benchmark Overview

The provided benchmark measures the performance of three different approaches to check if an element has a display property set to none:

1. Using getComputedStyle(element, null).getPropertyValue("display").indexOf('none') === -1
2. Using element.className.indexOf('hide') === -1
3. Using element.classList.contains('hide')

Approach 1: getComputedStyle

This approach uses the window.getComputedStyle function to retrieve the computed style of an element, specifically the display property value. The indexOf method is then used to check if 'none' is present in the value.

Pros:

• This approach is more accurate because it checks for the exact value of the display property.
• It's a standard JavaScript function that doesn't require any additional libraries.

Cons:

• This approach can be slower due to the overhead of using a function call and accessing the DOM.
• The performance difference between this and other approaches may not be noticeable in modern browsers, but it's still worth considering.

Approach 2: className

This approach uses the className property of an element to check if 'hide' is present. The indexOf method is used to find the presence of 'hide'.

Pros:

• This approach is faster because it only requires accessing a single property and performing a simple string search.
• It's also a standard JavaScript function that doesn't require any additional libraries.

Cons:

• This approach can be less accurate because it only checks for the presence of 'hide' in the class list, not the exact value of the display property.
• It may not work as expected if the element has multiple classes with different values (e.g., .class1.hide).

Approach 3: classList.contains

This approach uses the classList.contains() method to check if 'hide' is present in the class list of an element.

Pros:

• This approach is faster and more accurate than using className because it's designed specifically for checking class presence.
• It's a modern JavaScript function that's supported in most browsers.

Cons:

• This approach requires the use of the classList property, which may not be supported in older browsers or in certain environments (e.g., Internet Explorer).

Library Used

None of these approaches require any additional libraries beyond standard JavaScript functions. However, if you're using a library like jQuery, you might need to consider its performance impact on your benchmark.

Special JS Feature/Syntax

None of these approaches rely on any special JavaScript features or syntax that would affect their behavior or performance.

Alternatives

If you want to explore alternative approaches, here are a few options:

• Using document.querySelector and accessing the style attribute directly (which might be slower than using getComputedStyle)
• Using CSS APIs like window.CSS (if available in your browser)
• Optimizing the benchmark for specific use cases or requirements

Keep in mind that these alternatives may not offer significant performance improvements over the original three approaches.