How many instances???

[Renjith Ramachandran]

how can i get the number of instances of my clasess? there is one way like we can declare a static member variable and increment that in the constructor, but if you create a derived object, that count also increases in the base class. how can i prevent that ? i need to get the count of parent objects only. any idea? Ninety-eight percent of the thrill comes from knowing that the thing you designed works, and works almost the way you expected it would. If that happens, part of you is in that machine.

[try88]

just write two constructors function 路漫漫其修远兮，吾将上下而求索。

[S Senthil Kumar]

Decrement the counter by one in your derived class's constructor? Regards Senthil _____________________________ My Blog | My Articles | WinMacro

[toxcct]

and set the destructor as virtual

---

TOXCCT >>> GEII power
[toxcct][VisualCalc]

[Renjith Ramachandran]

hey how it is possible? how can i say other ppls to decrement parent clasess counter in your clasess? i need to maintain my class as an entity, i just need to know the number of instances of my base class Ninety-eight percent of the thrill comes from knowing that the thing you designed works, and works almost the way you expected it would. If that happens, part of you is in that machine.

[Renjith Ramachandran]

can u write the code for that ??? Ninety-eight percent of the thrill comes from knowing that the thing you designed works, and works almost the way you expected it would. If that happens, part of you is in that machine.

[S Senthil Kumar]

class Base
{
protected:
static int counter;

public:
Base() { counter++; }
};

int Base::counter;

class Derived : Base
{
public:
Derived()
{
counter--;
}
};

Regards Senthil _____________________________ My Blog | My Articles | WinMacro

[toxcct]

class CBase {
static int m_iCounter;

public:
CBase() {
m_iCounter++;
}

virtual ~CBase() {
    m\_iCounter--;
}

};

class CChild : public CBase {
//...
};

now, you could do this :

void foo() { //Counter == 0
CChild myChild1; //Counter == 1
CChild myChild2; //Counter == 2
{
CCHild myChild3; //Counter == 3
} //Counter == 2
myChild1.~CChild(); //Counter == 1
} //Counter == 0

when the program goes out a scope, the objects destructor is automatocally called. for a CCHild object, the CCHild destructor is firstly call, then its CBase destructor... was it well what you wanted ?

---

TOXCCT >>> GEII power
[toxcct][VisualCalc]

[S Senthil Kumar]

Writing a virtual destructor for a base class is generally a good idea, but is not absolutely necessary for this application. That apart, my interpretation of the OP's question was that he wanted to count only explicitly created instances of CBase, that's why I suggested decrementing it in derived class constructors. Regards Senthil _____________________________ My Blog | My Articles | WinMacro