Alphanumeric ID Code

Hello, I am learning C++.

I’m trying to determine how to to create a 7 digit I.D. code by accepting user input. The I.D. code needs to accept both digits and letters (e.g. C456W91). I understand how to create either an array of integers, OR anarray of characters but I am unsure how to go about combining integers and characters in this way.

Thanks for any help you might offer.