Area of the circle
Description
Define the Circle class, there is a private, double type attribute radius, which represents the radius of the circle. There is a public, often static data member of the double type, PI=3.14, which represents the pi. Define the getArea() and getRadius() methods to return the area and radius of the circle. Note: When defining the above two methods, ensure that the program can be executed correctly.
Input
A double type of data.
Output
See example.
Sample Input
3.15
Sample Output
PI=3.14
radius=2,area=12.56
radius=3.15,area=31.1566
Title given code
int main()
{
double radius;
cout<<"PI="<<Circle::PI<<endl;
const Circle c1(2);
cout<<"radius="<<c1.getRadius();
cout<<",area="<<c1.getArea()<<endl;
cin>>radius;
Circle c2(radius);
cout<<"radius="<<c2.getRadius();
cout<<",area="<<c2.getArea()<<endl;
return 0;
}
Note: The const object is given in the main function, so the getArea() and getRadius() functions add the const keyword between the parameter list and the body!
code:
#include<iostream>
using namespace std;
class Circle{
private:
double radius;
public:
static const double PI=3.14;
Circle(double r){
radius=r;
}
double getArea()const{
return PI*radius*radius;
}
double getRadius()const{
return radius;
}
};
int main()
{
double radius;
cout<<"PI="<<Circle::PI<<endl;
const Circle c1(2);
cout<<"radius="<<c1.getRadius();
cout<<",area="<<c1.getArea()<<endl;
cin>>radius;
Circle c2(radius);
cout<<"radius="<<c2.getRadius();
cout<<",area="<<c2.getArea()<<endl;
return 0;
}