Java is an object oriented language and some concepts may be new. Take breaks when needed, and go over the examples as many times as needed.

Armstrong Number in Java: A positive number is called armstrong number if it is equal to the sum of cubes of its digits for example 0, 1, 153, 370, 371, 407 etc.

//ChecktempNumber is Armstrong or not using while loop
package com.guru99;
 
public class ArmstrongNumber {
 
    public static void main(String[] args) {
        int tempNumber, digit, digitCubeSum;
 
        for (int inputArmstrongNumber = 0; inputArmstrongNumber < 1000; inputArmstrongNumber++) {
            tempNumber = inputArmstrongNumber;
            digitCubeSum = 0;
            while (tempNumber != 0) { 
                /* On each iteration, remainder is powered by thetempNumber of digits n */ 
                digit = tempNumber % 10;
 
                //sum of cubes of each digits is equal to thetempNumber itself
                digitCubeSum = digitCubeSum + digit * digit * digit;
 
                tempNumber /= 10;
 
            }
 
            //check giventempNumber and digitCubeSum is equal to or not 
            if (digitCubeSum == inputArmstrongNumber)
                System.out.println(inputArmstrongNumber + " is an Armstrong Number");
         } 
    } 
}

Output:

0 is an Armstrong Number
1 is an Armstrong Number
153 is an Armstrong Number
370 is an Armstrong Number
371 is an Armstrong Number
407 is an Armstrong Number