Question

How to print a particular member of a structure using pointer arithmetic? I have a structure with 2 members. I want to print out member j by manipulating the memory of the pointer to that structure.

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

typedef struct ASD
{
    int i;
    int j;
}asd;

void main (void)
{
    asd test;
    asd * ptr;

    test.i = 100; 
    test.j = 200;
    ptr = &test;

    printf("%d",*(ptr +1));

    _getch();
}

Answer 1

The pointer type needs to be right so that the increment adds the correct size:

printf("%d",*( ((int*)ptr) +1));

Edit: As any C programmer should know, using pointer arithmetic to access struct members is useless and dangerous. Useless because the -> operation is much more concise and precise in accessing a named member, and dangerous because naive use of pointer arithmetic will result in a number of issues. However, pointer arithmetic is what the OP asked for, so pointer arithmetic is what he got.