# Armstrong Number Program in JAVA

### What is Armstrong Number ?

In an Armstrong Number, the sum of power of individual digits is equal to number itself.

In other words the following equation will hold true

`xy..z = xn + yn+.....+ zn`

n is number of digites in number

For example this is a 3 digit Armstrong number

```370 = 33 + 73 + o3
= 27 + 343 + 0
= 370```

Examples of Armstrong Numbers

` 0, 1, 4, 5, 9, 153, 371, 407, 8208, etc.`

Let’s write this in a program:

## Java Program to check whether a number is Armstrong Number

• //ChecktempNumber is Armstrong or not using while loop
•
• package com.guru99;
•
• public class ArmstrongNumber {
•
• public static void main(String[] args) {
•
•
• int inputArmstrongNumber = 153; //Input number to check armstrong
•
•
• int tempNumber, digit, digitCubeSum = 0;
•
•
• tempNumber = inputArmstrongNumber;
•
• while (tempNumber != 0)
•
• {
•
•
• /* On each iteration, remainder is powered by thetempNumber of digits n
• */
•
• System.out.println(“Current Number is “+tempNumber);
•
• digit =tempNumber % 10;
•
•
• System.out.println(“Current Digit is “+digit);
•
•
• //sum of cubes of each digits is equal to thetempNumber itself
•
•
• digitCubeSum = digitCubeSum + digit*digit*digit;
•
•
• System.out.println(“Current digitCubeSum is “+digitCubeSum);
•
•
• tempNumber /= 10;
•
•
• }
•
•
•
• //check giventempNumber and digitCubeSum is equal to or not
•
•
• if(digitCubeSum == inputArmstrongNumber)
•
•
• System.out.println(inputArmstrongNumber + ” is an Armstrong Number”);
•
•
• else
•
•
• System.out.println(inputArmstrongNumber + ” is not an Armstrong Number”);
•
•
• }
•
•
• }

Output

```Current Number is 153
Current Digit is 3
Current digitCubeSum is 27
Current Number is 15
Current Digit is 5
Current digitCubeSum is 152
Current Number is 1
Current Digit is 1
Current digitCubeSum is 153
153 is an Armstrong Number```

## Java Program to Print Armstrong numbers from 0 to 999

• //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```

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