(defparameter *a* "intitial")
;; => *A*
(princ *a*)
;; => intitial
;;
;; "intitial"
- the surrounding asterisks (or 'earmuffs') are a convention to indicate that the variable is DYNAMIC or SPECIAL. More later.
(setf *a* "updated")
;; => "updated"
(princ *a*)
;; => updated
;;
;; "updated"
- A variable can be updated by using
setf.
(setf *a* 42)
;; => 42
(princ *a*)
;; => 42
;;
;; 42
- Common lisp is dynamically typed so we are free to change variables to different types