C / C++ / MFC

// the .h (header) file
class a
{
public:
    void somefunc();
};

// in the .cpp (implementation) file
void a::somefunc()
{
    // code
}

class a
{
private:
    int nPrivateInt;
public:
    int nPublicInt;
};

class b
{
public:
    friend class a;
    void somefunc()
    {
        // do something
        a InstanceOfa;
        InstanceOfa.nPrivateInt = 0; // this is possible because a is a friend!
    }
};

// somewhere in the code
a InstanceOfA;
InstanceOfA.nPrivateInt = 0; // not possible because nPrivateInt is private!
InstanceOfA.nPublicInt = 0; // possible because nPublicInt is public!

Class1 instanceOfClass1;<br />
Class2 instanceOfClass2;<br />
<br />
// "m_ptrToClass1Object" is a public member of class Class2<br />
instanceOfClass2.m_ptrToClass1Object = &instanceOfClass1;

<br />
class ClassB<br />
{<br />
public:<br />
	void ActionB();<br />
};<br />
<br />
class ClassA<br />
{<br />
public:<br />
	ClassB* m_pB;<br />
	void ActionA();<br />
};

<br />
ClassA a; //create an instance of each<br />
ClassB b;<br />
<br />
a.ActionA(); //call methods from A directly<br />
<br />
a.m_pB = &b; //pass a pointer to the instance of B to A<br />
a.m_pB->ActionB(); //call B through A using the stored pointer<br />

void CForemanView0::OnInitialUpdate() <br />
{<br />
	CFormView::OnInitialUpdate();<br />
<br />
        // PUT CODE HERE<br />
}