Want to ask you how to call functions in a class in the main function, I don't know this why

 # include & lt; Iostream> 
using namespace std; 
Const double PI=3.14159; 
The class Figure {
Public: 
Virtual double area ()=0; 
Virtual double volume ()=0; 

}; 
The class Circle: public Figure {
Public: 
Circle (double r) : the radius (r) {} 
Double getR () {
Cout<" Please enter the radius "& lt; Cin> The radius. 
Return the radius. 


} 
Double setR () {
Return the radius. 
} 


Private: 
Double radius;//R 
}; 


The class Sphere: public Circle {//ball 
Public: 
Sphere (double x) : Circle (x) {} 

Virtual double volume () {
Double a=setR (); 
Return four thirds * PI * a * a * a; 
} 
Virtual double area () {
Double a=setR (); 
Return 4 * PI * a * a; 
} 
}; 
The class Cylinder: public Circle {//Cylinder 
Public: 
Cylinder (double a, double b) : Circle (a), height (b) {} 
Virtual double volume () {
Double a=setR (); 
Return a * a * PI * height; 
} 
Virtual double area () {
Double a=setR (); 
Return a * a * PI * 2 + 2 * PI * a * height; 
} 
Private: 
A double height;//H 

}; 
Int main () {
Circle, Circle getR (); 
The Sphere (Circle. The sp setR ()); 
Cylineder cy (Circle. SetR (), 3.0); 
Cout<" Surface area of the circle is: "& lt; Cout<" The volume of the circle is: "& lt; Cout<" Surface area of the cylinder is: "& lt; Cout<" The volume of a cylinder is: "& lt; return 0; 
} 

CodePudding user response:

Circle the Cir;
Cir. GetR

CodePudding user response:

So or not ah

CodePudding user response:

Circle Circle;
Circle. GetR ();
The Sphere (circle. The sp setR ());
Cylineder cy (circle. SetR (), 3.0);
Cout<" Surface area of the circle is: "& lt; Cout<" The volume of the circle is: "& lt; Cout<" Surface area of the cylinder is: "& lt; Cout<" The volume of a cylinder is: "& lt; CodePudding user response:

You didn't reflect this polymorphic
Circle Circle;
Circle. GetR ();
The Sphere (circle. The sp setR ());
Cylineder cy (circle. SetR (), 3.0);
Circle * c1=& amp; sp;
Circle * c2=& amp; Cy.
Cout<" Surface area of the circle is: "& lt; Cout<" The volume of the circle is: "& lt; Cout<" Surface area of the cylinder is: "& lt; Cout<" The volume of a cylinder is: "& lt; CodePudding user response:

Your estimate is not very understand what is the class, what is the object that is instantiated