How to write attribute without parameter in Pug (Jade)?

Question

HTML

When I write nav.dropdown.menu(data-dropdown-menu) :

<nav class="dropdown menu" data-dropdown-menu="data-dropdown-menu" role="menubar">

How to make an output like this: Thanks in advance
<nav class="dropdown menu" data-dropdown-menu>

Answer 1

Specify doctype htmlat the beginning of the file.

Answer 2

No way.
Maximum, you can deduce like this: But why? And doctype has nothing to do with it. An implementation like the one you want works with attributes of type boolean , but data attributes are not - they are designed to store some kind of information.