Answer:
Following are the program to this question:
#include <iostream>//header file
using namespace std;//namespace
class Val //defining abstract class
{
public://use access specifier
virtual int squ()=0;//declaring a method squ
void setval(int x) //defining a method setval
{
a=x;//holding value in a variable
}
protected://use access specifier
int a;//defining integer variable
};
class square: public Val //defining a class square that inherit abstract class
{
public://use access specifier
int squ() //defining squ method
{
return (a*a); //return square value
}
};
int main() //main method
{
square s;//creating class object
s.setval(5);//calling setval method
cout << "The square value is: " << s.squ() << endl;//print value by calling squ method
}
Output:
The square value is: 25
Explanation:
In the above code a two-class "Val and square" is declared, in which val is abstract class, in a method squ is declared, and setval is used to set the value.
In the next step, the square class inherits Val and defines the squ method, and uses the return keyword to return its calculated value.
In the main method square class object is created and set the setval value and call the squ method and print its value.
