Example: Java Program to Check Armstrong Number or Not using While loop

// Java Program to Check Armstrong Number or Not using While loop
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);

        int x, y, z, rem, n = 0;
        double r = 0.0;
        // x - To store the input number
        // y & z - To store the storage of original input number to check
        // rem - To store the reminder
        // r - To store the result variable

        System.out.println("-----Enter the integer number-----");
        x = in.nextInt();

        z = y = x;

        while (y != 0) {
            y /= 10;
            ++n;
        }

        while (z != 0) {
            rem = z % 10;
            r += Math.pow(rem, n);
            z /= 10;
        }

        // if x is equal to r, the number is an Armstrong number
        if ((int) r == x) {
            System.out.println("\n" + x + " is an Armstrong number.");
        } else {
            System.out.println("\n" + x + " is not an Armstrong number.");
        }
    }
}