Variable's scope in a switch case [duplicate]

Question

I think I don't understand how the scope works in a switch case.

Can someone explain to me why the first code doesn't compile but the second does ?

Code 1 :

 int key = 2;  switch (key) {  case 1:       String str = "1";       return str;  case 2:       String str = "2"; // duplicate declaration of "str" according to Eclipse.       return str;  } 

Code 2 :

 int key = 2;  if (key == 1) {       String str = "1";       return str;  } else if (key == 2) {       String str = "2";       return str;  } 

How come the scope of the variable "str" is not contained within Case 1 ?

If I skip the declaration of case 1 the variable "str" is never declared...

Answer 1

I'll repeat what others have said: the scope of the variables in each case clause corresponds to the whole switch statement. You can, however, create further nested scopes with braces as follows:

int key = 2; switch (key) { case 1: {     String str = "1";     return str;   } case 2: {     String str = "2";     return str;   } } 

The resulting code will now compile successfully since the variable named str in each case clause is in its own scope.