post_class function makes it really easy to write out a variety of class names to post containers that give us a finer-level of control when working on styling WordPress posts.
But there are times in which you may want to actually add a custom class to a post (or to a single post) depending on the nature of the content of the most.
And sure, you can easily add additional parameters to the
post_class function, but those are still static parameters that will be applied to every posts.
What about in cases where you want to add a class if, say, no more tag is present in the content?