### Java program to find the sum of all digits of a number :

In this tutorial, we will learn how to find the sum of all digits of a number in Java. Algorithm we are using is as below :

### Algorithm :

1. Start one *infinite* loop. This loop will run infinite times till user insert *‘-1’* as input.

2. Take the number from the user as input.

3. Declare one variable as *‘0’* to store the sum.

4. Using one ‘*while*‘ loop, get the *modulo 10* of the number and add it to the sum. If the number is *123*, get *‘123%10’ i.e. 3* and add it to sum.

5. Now, divide the number *by 10* and set it as new value. i.e. for *123, set it to 123/10 = 12*

6. Do this till the number become* ‘0’.*

7. Finally, Print out the result.

### Example program :

import java.util.Scanner; public class Main { private static void println(String message) { System.out.println(message); } public static void main(String[] args) throws java.lang.Exception { Scanner sc = new Scanner(System.in); while (true) { println(""); println("Enter a number ( -1 to exit ): "); int no = sc.nextInt(); if (no == -1) { break; } int sum = 0; while (no > 0) { sum += no % 10; no = no / 10; } println("Sum of all numbers is " + sum); } } }

### Example Output:

Enter a number ( -1 to exit ): 1 Sum of all numbers is 1 Enter a number ( -1 to exit ): 12 Sum of all numbers is 3 Enter a number ( -1 to exit ): 123 Sum of all numbers is 6 Enter a number ( -1 to exit ): 1234 Sum of all numbers is 10 Enter a number ( -1 to exit ): 12345 Sum of all numbers is 15 Enter a number ( -1 to exit ): 123456 Sum of all numbers is 21 Enter a number ( -1 to exit ): -1 Process finished with exit code 0