Armstrong Number in Java
A number is said to be an Armstrong number when the summation of each
digit cube of a number is equal to the original number.
Example 0, 1, 153, 370, 371, 407 etc.
Let’s check 153 is an Armstrong number or not.
153 = (1 * 1 * 1) + (5 * 5 * 5) + (3 * 3 * 3)
153 = 1 + 125 + 27 is equal to 153.
Check another number 407 is an Armstrong number or not.
407 = (4 * 4 * 4) + (0 * 0 * 0) + (7 * 7 * 7)
407 = 64 + 0 + 343 is equal
to 407 so it is an Armstrong
Java program to check Armstrong's number.
public class ArmstronNumber
{
public static void
main(String args[])
{
int num; // Number to Check Armstrong no.
int temp; // temp variable to store the number
int digit; // last digit taker
int arm=0; // variable to store the cube of a digit
num = 153; // number to be checked
temp = num; // store the number
while(num != 0)
{
digit = num %
10;
arm = arm + digit * digit * digit;
num = num / 10;
}
if(temp == arm)
System.out.println("Armstrong
Number");
else
System.out.println("Not Armstrong number");
}
}
In the above program, we have taken 153 as an example for checking
the Armstrong number. We have taken each digit cube and summed it up to
variable arm then check it, if it is equal to 153 then it is an Armstrong number.
Java Program to Check Armstrong Number with method
import java.util.*;
public class ArmstronNumWithMethod
{
int num; // Number to Check Armstrong no.
int digit; // last digit taker
int arm=0; // variable to store the cube of a
digit
// method
int armstronNumber(int
n)
{
num = n;
while(num != 0)
{
digit = num %
10;
arm = arm + digit * digit * digit;
num = num / 10;
}
return arm;
}
// main method started
public static void
main(String args[])
{
int number, armNum;
Scanner sc = new
Scanner(System.in);
// object of the
class
ArmstronNumWithMethod ob = new ArmstronNumWithMethod();
System.out.println("Enter a number :");
number =
sc.nextInt();
// call the method
with number as parameter
armNum =
ob.armstronNumber(number);
if(number == armNum)
System.out.println(number + " is Armstrong Number");
else
System.out.println(number + " is not Armstrong number");
} // main method end
} // end of class
More Java program
