Armstrong number program in Java

In this section you will learn how to check whether a number Armstrong or not. In this program we are taking the input from the user.

What is armstrong number?

An Armstrong number of three digits is an integer such that the sum of the cubes of its digits is equal to the number itself.

Example of armstrong number:

	
    7 = 7^1
    371 = 3^3 + 7^3 + 1^3(27+343+1)
    8208 = 8^4 + 2^4 +0^4 + 8^4 (4096 + 16 + 0 + 4096)
	

What is scanner function?

Scanner function is use to take the input from user in java.

How program will work?

• First import the scanner package at top of program.
• Second initialize five integer variable like (n, a, num, temp, sum).
• Assign the default value to sum variable like sum=0.
• Now perform multiplication operation with arithmetic operator (*).
• Finally show the result on output screen.

Program of armstrong number in Java

	import java.util.Scanner;

	class Armstrong
	{
		public static void main(String arg[])
		{
			int n, a, num, temp, sum=0;
			Scanner sc = new Scanner(System.in);
			System.out.println("ENTER A NUMBER:- ");
			n = sc.nextInt();
			num = n;
			do
			{
				temp = n%10;
				a = temp*temp*temp;
				sum = sum + a;
				n = n/10;
			}
			while(n!=0);
			if(sum == num)
			{
				System.out.println(num+" IS ARMSTRONG NUMBER.");
			}
			else
			{
				System.out.println(num+" NOT A ARMSTRONG NUMBER.");
			}
		}
	}

Output:

	ENTER A NUMBER:- 371
	371 IS ARMSTRONG NUMBER.