Answer Posted / apple dugar

A virtual function that is initialized to zero (0) is
referred to as pure virtual function.It has no body and
hence also known as do-nothing or the dummy function.
Example: virtual void show()=0;

A class containing one or more pure virtual functions is
called an Abstract class, which means an instance of such
class can't be created (but pointer to that class can be
created).We should use pure virtual function if we do not
want to instantiate a class but make it act as a base class
for all the classes that derive from it.An important thing
to note about pure virtual functions is that these
functions must be overridden in all the derived classes
otherwise the compile would flag out an error.

Sample program:

class alpha
{
public:virtual void show()=0; //pure virtual function
};
class beta:public alpha
{
public:void show() //overriding
{
cout<<"OOP in C++";
}
};
void main()
{
alpha *p;
beta b;
p=&b;
p->show();
}

Output: OOP in C++

What is the difference between a type-specific template friend class and a general template friend class?

983

---

Explain selection sorting. Also write an example.

1048

---

What are guid?

1249

---

What does iomanip mean in c++?

1203

---

Is map thread safe c++?

1080

---

Describe new operator?

1163

---

What does obj stand for?

1169

---

What do you mean by overhead in c++?

1095

---

What is ios flag in c++?

1214

---

Define a conversion constructor?

1094

---

What is null pointer and void pointer and what is their use?

1102

---

Is c++ map a hash table?

1028

---

Is c the same as c++?

1009

---

Can we use this pointer in a class specific, operator-overloading function for new operator?

1104

---

Which of the following is not a valid declaration for main() a) int main() b) int main(int argc, char *argv[]) c) They both work

1082

---