A few months ago this article pointed out that classes could actually be avoided all together from website development.

My question is, how efficient are the data selectors compared to class selectors?

A simple example would be to compare querying for elements with data-component='something' versus elements with class='class1 class2 something anotherClass'.

The [data-<attr>='<value>'] selector will check the value as a whole versus the class string that should be split. With this in mind, data atributes should be faster.

So, to refine the question, in the case of CSS, are we better off with class selector or data selector? And from a javascript point of view, will jQuery([data-component='something']) be more efficient than jQuery(.something)?