How to delete variable/forms in Lisp?

Question

In Python we have the del statement for deleting variables.

E.g:

a = 1
del a

What the equivalent of this in Lisp?

(setq foo 1)
;; (del foo) ?

Answer 1

In Common Lisp.

For symbols as variables:

CL-USER 7 > (setf foo 42)
42

CL-USER 8 > foo
42

CL-USER 9 > (makunbound 'foo)
FOO

CL-USER 10 > foo

Error: The variable FOO is unbound.

See:

• MAKUNBOUND (defined)
• SLOT-MAKUNBOUND (defined)
• FMAKUNBOUND (defined)