schwab@canisius.UUCP (Ann Schwab) (09/08/89)
I have just started taking a class in modula-2 and on our first project I noticed a small quirk with CARDINAL and INTEGER numbers. When you are reading in a number from the keyboard it seems to work on all types of numbers and characters. In doing some further research I found that when a negative number was put into a CARDINAL field then it would return a 0 and the program would still keep going. When a decimal number such as 9.87 or a series of characters were entered then it would return a number between 2014 and 2020 and again it kept on running. I was trying my hardest to crash my program with invalid input and I couldn't do it no matter how hard I tried. Does anyone out there know why this was happening and how you can check to make sure that the number inputted is really a CARDINAL or INTEGER number and then have an error message register?? This same problem happened to the whole class and no one knows why. Thanks in advance for any help that you can give. Ann Schwab in%"schwab@klaatu.canisius.edu"
MARKV@UKANVAX.BITNET ("MARK GOODERUM - UNIV. OF KANSAS ACS - MARKV@UKANVAX") (09/08/89)
What version of Modula-2 are you using!!!??? These symptoms sound suspiciously
like the Compiler is freely plugging the floating point into the CARDINAL
or some such rubbish.
-Mark Gooderum
MARKV@UKANVAX
P.S. Both of these conditions should cause a run time error, or at least
a retry if your ReadCard was written robustly.