Question

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

using namespace std;

union type{
            int a;
            char b;
            int *p;
            char *s;
            int arr[10];
};

int fn(union type *exp){

    exp->p = exp->p+1;
    cout << *(exp->p);
    cout << "\n";
return 0;
}

int main(){

    union type *str;
    str->a = 10;
    str->b = 'n';
    str->p = &(str->a);
    cout << (str->p);
    cout << "\n";
    fn(str);
    cout << str->p;
    cout << "\n";
return 0;
}

This code is giving me segmentation fault. Is it because i need to allocate memory to the union explicitly using malloc?? I am new to coding and trying to learn c++.

Answer 1

This code is giving me segmentation fault. Is it because i need to
allocate memory to the union explicitly using malloc??

Right. Your str pointer isn’t pointing to valid memory location, it even not initialized. So, before writing str->a you need to set str to something.