#include<conio.h>
#include<stdio.h>

void main() {
struct st {
int i;
struct st *j;
}t1,t2;
clrscr();
t1.i=123;
t2.i=456;
t1.j=&t2;
t2.j=&t1;
printf("%d\n%d",*t2.j,*t1.j);
}


checked it with compiler
*t2.j=123
*t1.j=garbage value;
can anybody explain me why ?

What do you get after correcting the errors?


I get 123 and 456, as you probably intended: http://ideone.com/JOFlQ

The errors were wrong return type of main, which wouldn't affect the output, and wrong arguments to printf, which results in undefined behavior.

PS: If your system is anything like this GCC/linux I tested on, printf() expects to see integer arguments in certain CPU registers: ESI for the first %d, EDX for the second %d. You're passing structs, which are stored on stack instead, and the registers contain whatever intermediate values they happen to have at this point of execution.

Oh I see the difference now.

Trying to call a pointer with " . " instead of " -> "

http://www.cplusplus.com/reference/std/new/operator%20new/