asked on

static class declaration

Suppose we have class declaration :

class A
{
......................
.....................
private:
static class A *pA;
};

My question is what is the use of the 'pA' variable and why is it defined static ?

Thanks...........

itsmeandnobodyelse

'static' means that his member exists once for all instances of the class, it is therefore a member of the class and not of an instance.

You may use this feature for counters or pointers to another class where only one instance exists, e. g.
static CMyApp* m_pApp;

Regards, Alex

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itsmeandnobodyelse

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jhshukla

>> My question is what is the use of the 'pA' variable and why is it defined static ?

so that it can be accessed even without instantiating an object of class A. of course, to dereference pA you will have to instantiate an object.

One possible use is to make it point to the latest instantiation of A. like:
A::A(){
pA = this;
}
A::~A(){
if(this == pA) pA=NULL;
}

tinchos

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