Have you ever seen a class name starting with
If the answer is not, then you can visit the GitHub repository and see the source of generated HTML. There are bunch of elements whose class are prefixed with
js- such as:
<meta class="js-ga-set" name="userId" content="...">
<meta class="js-ga-set" name="dimension1" content="...">
They are often used to manage the list of elements that we don't want to set id for (dynamic elements, for example). In these cases, we use the
document.querySelectorAll('js-xxx') method to retrieve the elements list.
In the other words, the
Follow this naming convention is helpful if you're working in a team. Other engineers will be aware of the class name, and don't remove them when refactoring the page.