Range checking on Say 4a

I'm working on the Java 4a (Say) assignment. Perhaps someone can shed some light on a my question.
Is it safe to assume that the person will enter a number of some form or should we check for that?
Thanks!

You need to make sure the number is in the proper range but you don't need to make sure it is a number.
Bill

Thanks. Now if I'm not mistaken, we need to check to see that the number is between 0 and 99. However, at the same time I checked to see that a single argument was passed, I also checked to see that the argument had a length <= 2, which I believe accomplishes the same thing as checking to see if the value is between 0 and 99.
I prefaced that line of code stating that I was checking to see that there was only one argument and that it had 2 or fewer digits.
So why am I getting the comment "Where is the range checking?"

"Write a program that will read in a number from 0 to 99 and spell out that number. The program must also report any values that are out of range."
You need to print a message to the user if the value is out of range.
[This message has been edited by Marilyn deQueiroz (edited February 28, 2001).]

Thanks. I guess that means that a different type of error message other than the usage error has to be given.
Thanks for the clarification.

Checking to see if the length of the argument is less than 2 doesn't really do the samething as check to see if it is 99 or less because I can type in "ab" and it will pass your range check. I know I said you don't have to make sure they entered a number, but you do need to make sure your range checking doesn't pass unless it is a valid response.
I am probably confusing you some, but I don't want to give you the solution without making you think about it.

Bill

Also negative single digit numbers like "-1" also have a length of two but it is not in the required range ...