Example: Armstrong Number in C++ using Class and Object

// Armstrong Number in C++ using Class and Object
#include <bits/stdc++.h>
#include <cmath>
using namespace std;

class Armstrong {
public:
    int p;
    float r = 0.00;

    // This method will check input number is Armstrong or not
    void CheckArmstrong(int x)
    {
        p = x;
        int q, rem, n = 0;

        // q - To store the storage of original input number to check
        // rem - To store the reminder
        // r - To store the result variable

        q = p;

        // store the number of digits of x in n
        for (q = p; q != 0; ++n) {
            q /= 10;
        }

        for (q = p; q != 0; q /= 10) {
            rem = q % 10;
            // store the sum of the power of individual digits in r
            r += pow(rem, n);
        }
    }

    // This method will print the final output of the program
    void ArmstrongNumber()
    {
        // if "p" is equal to "r", the number is an Armstrong number
        if ((int) r == p)
            cout << p << " is an Armstrong number.\n";
        else
            cout << p << " is not an Armstrong number.\n";
    }
};

// It's the driver function
int main() {
    int x; // To store the input number

    cout << "-----Enter the integer number-----\n";
    cin >> x;

    // It will create the instance of the `Armstrong` class
    Armstrong AM;

    // It will produce the final output
    AM.CheckArmstrong(x);
    AM.ArmstrongNumber();
    
    return 0;
}