In this program, You will learn how to perform arithmetic calculations using a virtual function in C++.

```
virtual void calculate() {
//statement
}
```

```
#include<iostream>
using namespace std;
class First {
public:
virtual void calculate() {
cout << "Arithmetic calculation";
}
};
class Second : public First {
public:
int x, y, res;
int ch;
void calculate() {
cout << "Enter 1 For Addition :";
cout << "\nEnter 2 For Subtraction :";
cout << "\nEnter 3 For Multiplication :";
cout << "\nEnter 4 For Division :";
cout << "\nEnter 5 For Mode :\n";
cin >> ch;
switch (ch) {
case 1:
{
cout << "\nEnter Two Numbers :";
cin >> x >> y;
res = x + y;
cout << "\nResult is :" << res;
break;
}
case 2:
{
cout << "\nEnter Two Numbers :";
cin >> x >> y;
res = x - y;
cout << "\nResult is :" << res;
break;
}
case 3:
{
cout << "\nEnter Two Numbers :";
cin >> x >> y;
res = x * y;
cout << "\nResult is :" << res;
break;
}
case 4:
{
cout << "\nEnter Two Numbers :";
cin >> x >> y;
res = x / y;
cout << "\nResult is :" << res;
break;
}
case 5:
{
cout << "\nEnter Two Numbers :";
cin >> x >> y;
res = x % y;
cout << "\nResult is :" << res;
break;
}
default:
cout<<"\nInvalid selection";
}
}
};
int main() {
First *f;
Second s;
f = &s;
f->calculate();
return 0;
}
```

```
Enter 1 For Addition :
Enter 2 For Subtraction :
Enter 3 For Multiplication :
Enter 4 For Division :
Enter 5 For Mode :
2
Enter Two Numbers :10 5
Result is :5
```