Thread: structure and typedef

Hi,
I have seen the following code and was surprised

Code:

#include <stdio.h>

int main()
{
   typedef struct name name1;

   struct name
   {
       int i;
       char array[10];
   };
 name1 name2;
 name2.i = 13;
 printf("%d",name2.i);
 return 0;
}

In the line typedef struct name name1, the name structure is not yet defined and why the compiler is not giving any error. Also i cannot define a structure within a structure that is cannot reference itself but i can define a pointer to reference itself. Can someone please explain me what is the logic involved in all these things.

Thanks and regards,
Satya

typedef merely renames things; it does not require any information about what that thing is. As long as that thing gets defined, everyone's happy.

As to the second question, of course a structure cannot contain a copy of itself, because that copy must then contain another copy of itself, and that copy must then contain another copy of itself, .... A pointer is a different type of data, and does not cause an infinite loop as the above would.