1. Construct a class named sphere that has a double-precision data member named radius. The class should have the following class functions: i. A constructor with the default values of 1 for radius data member. ii. An accessor function named showData() that displays a sphere’s radius. iii. A mutator function named setData() to set a sphere’s radius. iv. A class function named surfaceArea() that calculates and displays a sphere’s surface area. v. A class function named volume() that calculates and displays a sphere’s vol

ume.

Here's an example implementation of the sphere class in C++:

#include <iostream>
#include <cmath>

class sphere {
private:
    double radius;
public:
    sphere() {
        radius = 1.0;
    }

    void showData() {
        std::cout << "Sphere radius: " << radius << std::endl;
    }

    void setData(double r) {
        radius = r;
    }

    double surfaceArea() {
        return 4 * M_PI * radius * radius;
    }

    double volume() {
        return 4.0 / 3.0 * M_PI * pow(radius, 3);
    }
};

int main() {
    sphere mySphere;
    mySphere.showData();
    mySphere.setData(2.0);
    std::cout << "Sphere surface area: " << mySphere.surfaceArea() << std::endl;
    std::cout << "Sphere volume: " << mySphere.volume() << std::endl;
    return 0;
}

In this implementation, the sphere class has a private data member `radius` and five public member functions:

- A default constructor that initializes the `radius` to 1.0.
- An accessor function `showData()` that displays the current value of `radius`.
- A mutator function `setData()` that sets the value of `radius`.
- A class function `surfaceArea()` that calculates and returns the surface area of the sphere.
- A class function `volume()` that calculates and returns the volume of the sphere.

In the `main()` function, we create a `sphere` object `mySphere`, display its initial radius using the `showData()` function, set its radius to 2.0 using the `setData()` function, and then display its surface area and volume using the `surfaceArea()` and `volume()` functions, respectively.