Question is
Do simple validation of data entered into a Book; for example, accept ISBNs only of the form n-n-n-x where n is an integer and x is a digit or a letter. Store an ISBN as a string.
Is there anyway to take a string and put it into the input stream? I guess the checking will be easy then.
I've recently done that for an assignement. What you wanna do is to get each of the Block of Numbers (separated by -) and check certain things on those 'Blocks'. Or you could go character by character, but first method is most efficient.