Let’s learn armstrong number in java using recursion.

## Armstrong number in java using recursion

Let’s check for armstrong number using recursion.

In java, a function that calls itself is called recursion.

Here’s the program to check armstrong number using recursion.

import java.util.Scanner; class RecursionArmstrong { int number, sum; RecursionArmstrong(int num1) { number = num1; sum = 0; } long powerOf(int a, int b) { if(b == 0) { return 1; } else { return a * powerOf(a, b - 1); } } void executePowerOf() { int d = number, r; long total = (long)sum; while(d > 0) { r = d % 10; d = d / 10; total = total + powerOf(r, 3); } if(number == total) { System.out.println("Given number is Armstrong number."); } else { System.out.println("Not an Armstrong number."); } } public static void main(String[] args) { Scanner sc = new Scanner(System.in); System.out.print("Please enter the number: "); int num = sc.nextInt(); RecursionArmstrong obj = new RecursionArmstrong(num); obj.executePowerOf(); sc.close(); } }

**Output:**

Please enter the number: 153

Given number is Armstrong number.

Also read – nested classes in java