Measuring the performance of different approaches to check if an HTML element has a certain class can be useful in various web development scenarios.

Benchmark Overview

The provided benchmark compares two approaches:

1. className.includes(): This method checks if the className property of an HTML element contains a specific string.
2. classList.contains(): This method checks if the classList property of an HTML element contains a specific string.

Pros and Cons of Each Approach

className.includes()

• Pros:
  • Widely supported by most browsers, including older versions that may not support classList.
  • Simple to implement.
• Cons:
  • Can be slower than classList.contains() due to the use of the includes() method, which scans through the string for a match.
  • May return false positives if the element has multiple classes with similar names.

classList.contains()

• Pros:
  • Faster than className.includes(), as it only checks for exact matches in the classList array.
  • More accurate, as it reduces the likelihood of false positives.
• Cons:
  • Not supported by older browsers that do not implement the Web APIs (e.g., IE 8-10).
  • Requires more code to set up and clean up the classList property.

Library Used

The benchmark uses the Web APIs, specifically:

1. document.getElementById(): Retrieves an HTML element by its ID.
2. element.classList: Accesses the classList property of an HTML element.

Note that classList is a part of the W3C web standards, and most modern browsers support it. However, older browsers may not have this feature or might require additional code to implement it.

Special JS Features/Syntax

This benchmark does not use any special JavaScript features or syntax beyond what's required for basic Web API functionality.

Other Alternatives

If the goal is to check if an HTML element has a certain class, other alternatives could include:

1. element.getAttribute('class') == 'your-class-name': This method uses the getAttribute() method to retrieve the value of the class attribute and compares it with the target class name.
2. Using a library like jQuery or Lodash, which provide utility functions for working with classes on HTML elements.

However, these alternatives may not be as efficient or reliable as using the native Web APIs (classList.contains()) in modern browsers.