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From: englfz@jetson.uh.edu
Newsgroups: comp.sys.mac.hypercard
Subject: Re: Checking for a named object sans error if nonexistant
Message-ID: <6777.26c6bdce@jetson.uh.edu>
Date: 13 Aug 90 19:48:46 GMT
References: <5611@uwm.edu> <43714@apple.Apple.COM>
Distribution: usa
Organization: University of Houston
Lines: 31

In article <43714@apple.Apple.COM>, bc@Apple.COM (bill coderre) writes:
> John Bowden:
> |I have a stack that creates other stacks and I need to verify whether
> |certain stacks were so created. 
 
> I'll summarize his second question:
> "Is there a way to determine whether a certain (object) exists?"
> 
> Well, in HC 1.x, no. 
> 
> bill coderre, consultant to Apple

The way I check to see if an object (field, button or something) exists
and then get its name looks something like the following:

	on checkfield
	  if the number of card fields > 0 then
          put the name of cd field 1 into fieldname
	end checkfield

With this approach, it only gets the name if a field exists, and therefore
won't give you the "Never heard of..." message if you are checking 
for the name of a nonexistant somethingorother.

Hope this helps


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 Ed Gibler                              University of Houston
 ENGLFZ@JETSON.uh.edu                English Computer Writing Lab
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