Before buying a book

read this book, if you understand it, then that's ok, if not then try to find a good one to buy
This book is called (Learn C++ in 21 days)
to download it
[link removed]
...

Yeah, you didn't even specify if
case 1: ........ // is a function or not?

if yes, then you shouldn't write the type of the parameters
as RenjithVR said

if it is not a function then!! what is...