cons object-1 object-2 → cons

object-1 — an object.

object-2 — an object.

cons — a cons.

Creates a fresh cons, the car of which is object-1 and the cdr of which is object-2.

(cons 1 2) → (1 . 2) 
(cons 1 nil) → (1) 
(cons nil 2) → (NIL . 2) 
(cons nil nil) → (NIL) 
(cons 1 (cons 2 (cons 3 (cons 4 nil)))) → (1 2 3 4) 
(cons 'a 'b) → (A . B) 
(cons 'a (cons 'b (cons 'c '()))) → (A B C) 
(cons 'a '(b c d)) → (A B C D)

list

If object-2 is a list, cons can be thought of as producing a new list which is like it but has object-1 prepended.