question2.cpp

/*
 * Write a program that asks a user to input the radius, then the program calculates the
 * volume of a sphere (the formula for the volume is (4/3) πr^3). Use the inbuilt exponential
 * function in C++ to compute (r^3).
 */

#include <iostream>
#include <cmath>
using namespace std;

int main() {
    // Declaration of variables
    double radius, volume;

    // Prompt the user to enter the radius of the sphere
    cout << "Enter the radius of the sphere: ";
    cin >> radius;

    if (cin.fail()) {
        // Reject strings
        cout << "Invalid input! Please enter a number.";
        return 1;
    } else if (radius < 0) {
        // Reject negative values for the radius
        cout << "Radius cannot be negative!";
        return 1;
    } else {
        // Calculate and display the volume of the sphere
        volume = (4.0/3.0) * M_PI * pow(radius, 3);
        cout << "The volume of the sphere with radius " << radius << " is " << volume << " cubic units!\n";
        return 0;
    }

}