strange problem about delete

Hi, here is the code:

Code:

---

#include <iostream.h>
class A
{
private:
        int i;
        public:
        void test(){cout<<"test"<<endl;}

};





int main()
{

  A* pt = new A;
  delete pt;
  pt = NULL;
  cout<<pt<<endl;
  pt->test();
  return 1;
}

---

The pointer pt still call the function even it is deleted, what is reason? Thanks

> The pointer pt still call the function even it is deleted, what is reason?
Because the compiler turns it into
A::test(pt);

So long as you don't try and access any members of the class, I doubt there would be a problem.
The 'this' pointer which the class member function would see would be the NULL pointer.

The statement delete pt; deletes the object of the class it points to, however it's still a pointer to the a class obj (whether it exists or not). Class member functions still exist, but the object and its data members are deleted.

Compile this and see what it does...

Code:

---

#include <iostream>
using namespace std;

class TestClass
{
    public:
        TestClass();
        ~TestClass();
        void test(){ cout << "test " << i << endl; }
       
    private:
        int i;
};

TestClass::TestClass()
    : i(24)
{
    cout << "Constructor called" << endl;
}

TestClass::~TestClass()
{
    cout << "Destructor called" << endl;
}

int main()
{
    cout << "initializing TestClass *objPtr = new TestClass; instantiates objPtr" << endl;
    TestClass *objPtr;
    objPtr = new TestClass;
   
    cout << "\nobjPtr->test(); calls member function from TestClass before delete" << endl;
    objPtr->test();
   
    cout << "\ndeleting objPtr destroys object" << endl;
    delete objPtr;
   
    objPtr = NULL;
    cout << "\ncout << objPtr << endl; verifies pointer set to NULL" << endl;
    cout<< objPtr <<endl;
    cout << "\nobjPtr->test(); calls member function from deleted TestClass obj" << endl;
    objPtr->test();
   
    return 0;
}

---