Thread: delete pointer inside ?

howdy~

we can delete pointer like

Code:

delete pt;

and what about if a pointer has another pointer inside ? like code below:

Code:

class Test
{
    private:
        int* pt;
};
int main()
{
    Test* t;
    delete t;
}

when the time we delete t, can the pointer pt inside t also be removed ?

t is just a pointer to a test object. Your code does not tell t to point to any object. If you wrote Test * t = Test_Object (Where Test_Object was already defined in your code) deleting it should not delete the object.

Code:

#include <iostream>
using namespace std;

class A
{
public:
  A(){cout<<"A constructor"<<endl; data=new int;}
  ~A(){cout<<"A destructor"<<endl; delete data; }
private:
 int* data;  

};

int main()
{
A* aObj=new A;
cout<<"Deleting aObj"<<endl;
delete aObj;
cin.get();

}

The class destructor should handle any deallocation of private data members. When you use delete on a class it will call its destructor.

Originally Posted by JaWiB

The class destructor should handle any deallocation of private data members. When you use delete on a class it will call its destructor.

ie, the pointer inside will persist all the way if we didnt free it in class's constructor ?

Deleting the pointer to the allocated object will call that objects destructor. If the object itself has allocated any memory, the destructor has to delete this memory, or it will float around forever.

All memory allocated inside the class should be deleted in the destructor.

Originally Posted by nvoigt

Deleting the pointer to the allocated object will call that objects destructor. If the object itself has allocated any memory, the destructor has to delete this memory, or it will float around forever.

All memory allocated inside the class should be deleted in the destructor.

so if we forget to delete the pointer whin the body of Test's destructor will result in lack of memory and crash our machine, didnt i go wrongly here ?

Code:

class Test
{
    public:
        Test(int n) { pt = new int(n) };
        ~Test( delete pt; );
    private:
        int* pt;
}

anyway thanx guys for all reply~