Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!usc!apple!jdevoto
From: jdevoto@Apple.COM (Jeanne A. E. DeVoto)
Newsgroups: comp.sys.mac.hypercard
Subject: Re: Why no 'case' statement in Hypertalk?  Suggestions?
Message-ID: <53699@apple.Apple.COM>
Date: 6 Jun 91 05:26:39 GMT
References: <1991Jun4.234844.1280@cognet.ucla.edu>
Organization: Apple Computer Inc., Cupertino, CA
Lines: 67

In article <1991Jun4.234844.1280@cognet.ucla.edu>
earl@cogdev.cognet.ucla.edu (Earl Williams) writes:
>Is there really no 'case' statement in Hypertalk, or am I missing its
>equivalent?  For simple keypress trapping, I'd like to do something like
>the following:
>
>on keyDown key
>  case
>    key = 'a' then do this else
>    key = 'b' then do that else
>    key = 'c' then do the other
>  end
>end keyDown
>
>Instead, I have to use standard if-then-else statements which, when
>formatted, give the false impression that I'm doing nesting.
>
>on keyDown key
>  if key = 'a' then do this else
>    if key = 'b' then do that else
>      if key = 'c' then do the other
>      end if
>    end if
>  end if
>end keyDown
>
>This is extremely inelegant, if not confusing (when used in a more
>complex example than this, of course.

Write your conditional like this:

  if key is "a" then do this
  else if key is "b" then do that
  else if key is "c" then do the other

Or, if your statements are more than one line (even if they're not, if
you're a neatness freak or want complete clarity when using nested ifs):

  if key is "a" then
    do this
  else if key is "b" then
    do that
  else if key is "c" then
    do the other
  end if

You can embellish this with an exception case at the end:

  if key is "a" then
    do this
  else if key is "b" then
    do that
  else if key is "c" then
    do the other
  else
    do something else
  end if

Just one end if, at the end, and no Vogage to the Righthand Edge of
the Script Editor.
-- 
========= jeanne a. e. devoto ========================================
 jdevoto@apple.com     |  You may not distribute this article under a
 jdevoto@well.sf.ca.us |  compilation copyright without my permission.
______________________________________________________________________
 Apple Computer and I are not authorized      |        CI$: 72411,165
 to speak for each other.                     |