Hi Tanuj, EXC_BAD_ACCESS means that there is some bug in the memory management of your program. It is trying to write at a memory address that has not been initialised.

This is exactly what is happening in your program, the members of the user struct first and last are char pointers, and currently, as they have not been allocated, they both point to NULL (@0x0).

It is not a valid address, and thus the program cannot write your input there, it would return a segmentation fault, which is exactly what is happening.

Here is a reviewed version of your program that should work:

#include <stdio.h>
#include <stdlib.h>

typedef struct {
    char * first;
    char * last; 
} name;

int main() {

    name user;

    // Allocate a char pointer for both first and last name strings
    // It tells your program where to store the store your inputs.
    user.first = malloc(sizeof(char *));
    user.last = malloc(sizeof(char *));

    printf("First name:");
    scanf("%s", user.first);

    printf("Last name:");
    scanf("%s",user.last);

    printf("%s %s\n", user.first, user.last);
}

I can explain further if you need it.