SICP Exercise 2.17

sicp

Question

Define a procedure last-pair that returns the list that contains only the last element of a given (nonempty) list:

(last-pair (list 23 72 149 34))
(34)

Answer

(define (last-pair l)
  (if (null? (cdr l))
      (car l)
      (last-pair (cdr l))))

(last-pair (list 23 72 149 34))

Results:

34