[racket] two question about DrRacket

The other option is to use values:

(define (p x)
  (values (+ x 10)
             (* x 10)))


That will return 2 values.

However, if you want to actually "display" the answers, you can:

(define (p x)
  (displayln (+ x 10))
  (displayln (* x 10)))


[]'s

Rodolfo Carvalho


On Thu, Jun 2, 2011 at 09:52, Hendrik Boom <hendrik at topoi.pooq.com> wrote:

> On Wed, Jun 01, 2011 at 02:57:41PM -0700, Yingjian Ma wrote:
> > Hi all,
> >
> > 1  I wrote
> >
> > (define (p x)
> >   (+ x 10)
> >   (* x 10)
> >   )
> >
> > The result of (p 4) is 40.  How can I display 14 and 40?
>
> You could return a list instead of the individual numbers.  The way
> you've coded it, the 14 is computed, then discarded.  Then the 40 is
> computed and returned.
>
> In LISP I'd code (list (+ x 10) (* x 10)).  I'm not quite sure if 'list'
> is still called 'list' in Scheme, though; a lot of the built-in function
> names have changed since the 60's, when I was heavily involved with
> Lisp. Look it up.
>
> -- hendrik
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