Set a 4-digit int code with cin

Question

I get the user to enter a 4-digit code. How can I secure that he does indeed enter a strictly 4-digit code (int) and not a 3-digit code for instance? How can I set that int to be of a 4-digit length?
Thanks a lot in advance! 😊

Answer 1

The best option is to take the input as a string and convert each character to an int to get the 4 digit code. This allows you to handle 4 digit code that start with 0 (for example 0123).

Answer 2

Hi and thanks for your answers! yes, 0663 is a valid 4 digit code. So, I guess it will indeed have to be a string, right? but then again, how can I make sure that the user does not enter characters? like a4b7 for instance? I want to make sure that the user will enter a 4 digit number from 0000 to 9999.

Answer 3

And can I prevent the user from entering anything else instead of numbers when entering that string variable?

Answer 4

Yes, you check each character to make sure it is an integer instead of an alphabetic character using a for loop, for example.