Only number can be write in case?

Answer 1

String and Enum can also be used as evaluation subject for `switch`. For the next time, please try to search the forum for possible similar thread topics. It helps in reducing duplicate questions 👍

https://www.csharp-examples.net/switch

(Edit)
I didn't see there was already answers when posting, refresh the page then I see 😆

Answer 2

Chars too are accepted.

char c = 'a';
switch(c){
case 'a':
Console.WriteLine("hi");
break;
}