hidden?

hidden?

This is a built-in turtle or link variable. It holds a boolean (true or false) value indicating whether the turtle or link is currently hidden (i.e., invisible). You can set this variable to make a turtle or link disappear or reappear.

See also hide-turtle, show-turtle, hide-link, show-link

Example:

set hidden? not hidden?
;; if turtle was showing, it hides, and if it was hiding,
;; it reappears