Strange behaviour when printing pointers

Question

I have the following code:

#include 

typedef struct {
  int* arg1;
  int  arg2;
} data;

int main(int argc, char** argv) {
  data d;
  printf         


        

Answer 1

You are accessing uninitialized values. This causes undefined behaviour (meaning that anything can happen, including the program crashing).

To fix, initialize values before using them, e.g.:

 data d = { 0 };