How do I print my procedure call in Scheme?

Question

I am trying to convert a C program to Scheme for an assignment I'm working on. The program is supposed to compute the area of a circle given the formal parameter (diameter, in this case). I think I have it figured out but I don't know how to print the actual value to verify it. I've tried just putting in the number into the print call. The way it is now is the method my book used. When I run the program with Dr. Racket I get:

print: undefined; cannot reference undefined identifier

(define pi 3.14159265)
(define test 5)
(define (areac d)
  (lambda (d)
    (* pi (/ d 2) (/ d 2)
       )))

(print (areac test))

Edit: Language is set to R5RS

Alexey Stankevich Alexey Stankevich · Accepted Answer · 2013-06-25T05:48:40

If you use "define", you don't have to use "lambda", because "define" is just convenient way to give the name to the lambda-procedure. Your code must look like this:

(define pi 3.14159265)
(define test 5)
(define (areac d)
   (* pi (/ d 2) (/ d 2)
        ))

(display (areac test))

How do I print my procedure call in Scheme?

2 Answers