Question

Why is it that in a C# switch statement, for a variable used in multiple cases, you only declare it in the first case?

For example, the following throws the error ‘A local variable named ‘variable’ is already defined in this scope’.

switch (Type) {     case Type.A:             string variable = 'x';                 break;     case Type.B:             string variable = 'y';                 break; } 

However, per the logic, the initial declaration should not be hit if the type is Type.B. Do all variables within a switch statement exist in a single scope, and are they created/allocated before any logic is processed?

Answer 1

I believe it has to do with the overall scope of the variable, it is a block level scope that is defined at the switch level.

Personally if you are setting a value to something inside a switch in your example for it to really be of any benefit, you would want to declare it outside the switch anyway.