ABACUS
*• ER*OR TRAPPING
Error trapping Controlled error handling is an absolute necessity for large programs.
These can save the user a lot of trouble from incorrect input. Very few programs are equipped with foolproof error checking. All the user has to
do is type in input that the computer can't accept, and the system may crash. Error trapping is another facet of user-friendliness.
However, you must first know how errors are handled in the first place, and where in the program the error occurs. You can't find the latter on your own, but there are a few rules you can follow to help your pro grams run error-free.
This chapter shows you how you can foolproof your programs from errors. Youfll read about routines that check for files on diskette without stopping from an error message, programs that generate requesters, and even a demonstration of easy menu creation.
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