PrintArmstrongNumbers.java

import java.util.Scanner;  
import java.lang.Math;  

public class PrintArmstrongNumbers {  

  // Function to check if the number is Armstrong or not  
  static boolean isArmstrong(int n) {   
    int temp, digits = 0, last = 0, sum = 0;   
    // Assigning n into a temp variable  
    temp = n;   
    // Loop execute until the condition becomes false  
    while (temp > 0) {   
      temp = temp/10;   
      digits++;   
    }   
    temp = n;   
    while(temp > 0) {   
      // Determines the last digit from the number      
      last = temp % 10;   
      // Calculates the power of a number up to digit times and add the resultant to the sum variable  
      sum +=  (Math.pow(last, digits));   
      //removes the last digit   
      temp = temp/10;   
    }  
    // Compares the sum with n  
    if (n == sum)   
      // Returns if sum and n are equal  
      return true;
    else 
      // Returns false if sum and n are not equal  
      return false;   
  }
  
  public static void main(String args[]) {     
    int num;   
    Scanner sc = new Scanner(System.in);  
    System.out.print("Enter the limit: ");  
    // Reads the limit from the user  
    num = sc.nextInt();  
    System.out.println("Armstrong Number up to " + num + " are: ");  
    for (int i = 0 ; i <= num ; i++) {
      // Function calling  
      if (isArmstrong(i))  
        // Prints the armstrong numbers  
        System.out.print(i + ", ");  
    }
  }   

}