Question

Note- can you rewrite the code in C++ if there is any existing code. Can you not use arrow -> operator.

Write a circle class that has the following member variables:

• radius: a double

• pi: a double initialized with the value 3.14159

The class should have the following member functions:

• Default Constructor. A default constructor that sets radius to 0.0.

• Constructor. Accepts the radius of the circle as an argument .

• setRadius. A mutator function for the radius variable.

• getRadius. An acccssor function for the radius variable

. • getArea. Returns the area of the circle, which is calculated as area = pi * radius * radius

• getDiameter. Returns the diameter of the circle, which is calculated as diameter = radius * 2

• getcircumforence. Returns the circumference of the circle, which is calculated as circumference = 2 * pi * radius

Write a program that demonstrates the circle class by asking the user for the circle's radius, creating a circle object, and then reporting the circle's area, diameter, and circumference.

Answer 1

CPP program :

//These are header files
#include <iostream>
using namespace std;
//CPP class
class circle{
//member variables
double radius;
double pi=3.14159;
public:
//Default Constructor
circle()
{
//A default constructor that sets radius to 0.0.
radius=0.0;
}
//Constructor. Accepts the radius of the circle as an argument .
circle(double r)
{
radius=r;
}
//setRadius. A mutator function for the radius variable.
void setRadius(double r)
{
radius=r;
}
//getRadius. An acccssor function for the radius variable
double getRadius()
{
return radius;
}
//getArea. Returns the area of the circle, which is calculated as area = pi * radius * radius
double getArea()
{
return pi*radius*radius;
}
//getDiameter. Returns the diameter of the circle, which is calculated as diameter = radius * 2
double getDiameter()
{
return radius*2;
}
// getcircumforence. Returns the circumference of the circle, which is calculated as circumference = 2 * pi * radius
double getcircumforence()
{
return 2*pi*radius;
}
};
//main() method
int main()
{
//This variable will store radius
double radius;
//This line will ask user radius
cout<<"Enter radius : ";
cin>>radius;//reading radius
//This line will create object of circle class
circle c;
//This line will call method to set the radius
c.setRadius(radius);
//This line will call method and display area of circle
cout<<"Area of circle with radius "<<c.getRadius()<<" is "<<c.getArea()<<endl;
//This line will call method and display diameter of circle
cout<<"Diameter of circle with radius "<<c.getRadius()<<" is "<<c.getDiameter()<<endl;
//This line will call method and display circumference of circle
cout<<"Circumference of circle with radius "<<c.getRadius()<<" is "<<c.getcircumforence()<<endl;

return 0;
}
======================================

Output :

input Enter radius : 10 Area of circle with radius 10 is 314.159 Diameter of circle with radius 10 is 20 Circumference of circle with radius 10 is 62.8318