User-defined object containing pointer breaks when stored in array

When I store a plain int in A and perform a simple get function:

#include <iostream>
class A
{
    int p;
public:
    void setint(int p_x);
    int getint();
};

void A::setint(int p_x) {p = p_x;} // set p (type int)

int A::getint() {return p;} // get p (type int)

int main()
{
    A arr_a[5];
    arr_a[0].getint();
}

it compiles and exits with code 0. However when I change int to int* and try to do the same:

#include <iostream>
class A
{
    int* p;
public:
    void setint(int p_x);
    int getint();
};

void A::setint(int p_x) {*p = p_x;} // set int pointed to by p (type int)

int A::getint() {return *p;} // get int pointed to by p (type int)

int main()
{
    A arr_a[5];
    arr_a[0].getint();
}

it compiles fine but exits with code 3221225477. Why is this so and is there still a way I can store pointers in A and store A in arrays?

>Solution :

In your 2nd case A arr_a[5] just create a array that contains 5 A. but
for every A, the pointer is an undefined number (maybe 0x0), so *p is a undefined behavior. You should add A::A() and A::~A() to manage your pointer in your class
just like this:

#include <iostream>
class A
{
    int *p;

public:
    A();
    ~A();
    void setint(int p_x);
    int getint();
};

A::A() : p(new int) {}
A::~A() { delete p; }

void A::setint(int p_x) { *p = p_x; } // set int pointed to by p (type int)

int A::getint() { return *p; } // get int pointed to by p (type int)

int main()
{
    A arr_a[5];
    arr_a[0].getint();
}