Thread: c switch declaration

Code:

#include<stdio.h>
main() 
{ switch (i) 
{ case 1: 
int a = 3;
 break; 
case 2:printf("hello"); break; } }

Code:

#include<stdio.h>
main()
{switch (i)      
{int a = 3;        
case 1:printf("%d",a);         
 break;       
 case 2:printf("hello");     
   break;     
 }   
 }

I know that the first code will produce an error..But why does in the second code a gets declared even though it is inside switch and in the first code it doesnot even declare it??

Really both are probably incorrect. But the first will compile if you add braces to your case statement:

Code:

switch (i)
{ 
   case 1:
   {
      int a = 3;
      // Do other things.
   }
   break;
   case 2:
      printf("hello"); 
      break; 
   } 
}

But remember that a will only be declared within that first case statement, not in any of the others. Also in the second snippet a is only available inside the switch statement, nowhere else.

Jim

@jimblumberg Thank you for your answer..but my question is that why the declaration is allowed inside switch block and not allowed inside case statement...although incase of inside switch you can have variable declared but not initialized..but why is this not possible in case of case statement??

The case statement without the braces doesn't create it's own scope which is required in order to declare a variable. I really don't know why you're allowed to create the variable inside the switch statement and not get either an error or warning message.

Jim