private:
inta;
friendclassB;
};
classB
{public:
voiddisplay1(At)
{t.a++;cout<<"display1:
a="<voiddisplay2(At)
{t.a--;cout<<"display2:
a="<};
voidmain()
{Aobj1;
Bobj2;
obj1.printa();
obj2.display1(obj1);
obj2.display2(obj1);
obj1.printa();
}
13.#include
usingnamespacestd;
classA{
public:
A(){cout<<"A"<~A(){cout<<"~A"<};
classB{
public:
B(){f();cout<<"B"<virtualvoidf(){cout<<"B:
:
f"<virtual~B(){cout<<"~B"<};
classD:
publicB{
public:
D(){cout<<"D"<voidf(){cout<<"D:
:
f"<virtual~D(){cout<<"~D"<private:
Aa;
};
voidmain()
{B*pB=newD;
pB->f();
deletepB;
}
14.#include
usingnamespacestd;
classMyclass
{public:
Myclass(inta,intb,intc);
voidPrintNumber();
voidPrintSum();
private:
intA,B,C;
staticintSum;
};
intMyclass:
:
Sum=10;
Myclass:
:
Myclass(inta,intb,intc)
{A=a;B=b;C=c;
Sum+=A+B+C;
}
voidMyclass:
:
PrintNumber()
{cout<<"Number="<voidMyclass:
:
PrintSum()
{cout<<"Sum="<voidmain()
{
MyclassM(3,7,10),N(14,9,1);
M.PrintNumber();N.PrintNumber();
M.PrintSum();N.PrintSum();
}