Re: TIB: Back to TI-BASICs
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Re: TIB: Back to TI-BASICs
On the TI-82/83 if you check for a variable (for example, Theta) and it
doesn't exist, it will return the value as 0. On the 85/86, if you check for
a variable and it doesn't exist, it will return an error. Spacefight on the
TI-82 uses this feature so that if you run one of it's subroutines without
going through the main program it will tell you what the subroutine is for.
Spacefight is available in the ticalc.org TI-82 BASIC archives. I, however,
use a TI-86 (formerly an 85) and I can't check for a variable if it doesn't
exist. I did find a way around this by using lists. This way you can have
subroutines display help information if you run them directly. It is also
helpful if you want to keep a high-score table-it won't give an error if the
variable doesn't exist. If anyone is interested in this program, I can send
it to you.
-Peter
Jody wrote:
> > and dangerous
> > because I have often deleted essential parts of programs. An easy
> > solution would be to do something like in Spacefight for the TI-82 (same
> > process would work for the '83) where subroutines check for the Theta
> > variable, and if it equals 0, it displays an error message.
>
> I'm curious what this means? I've never heard about checking for @ and
> displaying error messages. Just what does the calc do? Why would it
> display an error?
>
> Jody Snider
> jody1@alaska.net
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