Be careful. If cin.get() --but not cin.getline()-- reads an empty line it will set something called the failbit. The failbit prevents further input to cin.get(). Use cin.clear() to unset the failbit!
If you call cin.get() or cin.getline() and the input string is longer than the number of characters specified, these characters are put in a queue and will be submitted next time cin.get() or cin.getline() is called, but cin.getline() will also set the failbit. Be careful when you use these commands!