Question

Write a program using the class to find out the area of a circle and volume of a cylinder. [* area of a circle=πr2, the volume of a cylinder=πr2*h where h is the height of the cylinder and r is the radius of the circular end of the cylinder]

1. The member variable should be private

2. Use public member functions to execute your program.

3. Use set ( ) function to access the private members

4. Use another approach constructor function to access and initialize the private members

5. Use display function( ) to show the output of the program.

It's a C program.

Answer 1

#include <iostream>
using namespace std;

#define PI 3.14159

class AreaAndVolume {
private:
    double height;
    double radius;
public:
    AreaAndVolume() {
        height = 1;
        radius = 1;
    }

    AreaAndVolume(double height, double radius) : height(height), radius(radius) {}

    double getHeight() const {
        return height;
    }

    void setHeight(double height) {
        AreaAndVolume::height = height;
    }

    double getRadius() const {
        return radius;
    }

    void setRadius(double radius) {
        AreaAndVolume::radius = radius;
    }

    double circleArea() {
        return PI * radius * radius;
    }

    double cylinderVolume() {
        return PI * radius * radius * height;
    }

    void display() {
        cout << "Radius: " << radius << endl;
        cout << "Height: " << height << endl;
        cout << "Area of circle: " << circleArea() << endl;
        cout << "Volume of cylinder: " << cylinderVolume() << endl;
    }
};

int main() {
    AreaAndVolume areaAndVolume;
    areaAndVolume.setHeight(10);
    areaAndVolume.setRadius(5);

    areaAndVolume.display();
    return 0;
}