wp_nav_menu classes not named consistently

[iandunn]

The CSS classes assigned by wp_nav_menu seem to randomly switch between using dashes and underscores to separate words. For example

current_page_item
current-menu-item
menu-item-type-post_type

I can see a justification for making menu-item-type-post_type use an underscore to match the database field, function parameters, etc, but switching between dashes and underscore within the same class name is counter-intuitive. I don't see any reason why current_page_item and current-menu-item wouldn't match.

I think either dashes or underscores should be chosen and used exclusively across all class names.

[aaroncampbell]

current_page_item is legacy and there for backwards compatibility. Dashes are the new standard, so themes should be using the *menu-item* classes now.

[nacin]

I agree that post_type probably should have been post-type, but it's too late now, and we're not going to add a second class as we'd have to keep the old one.

Otherwise, Aaron is correct.

[GaryJ]

Is there actually any harm in adding a current-page-item class next to current_page_item class, if the underscore version could be some how marked as deprecated?

The longer the inconsistency remains, ultimately the more themes would need to be amended if the switch was made.