Java Program to Calculate the Sum of Digits of Given any Number.

import java.io.*;
class sum of digit{
 public static void main(String [] args) {  
    try{  
   BufferedReader din=new BufferedReader (new InputStreamReader(System.in));
   
   int n,r,s;
   System.out.println("Please enter the number to find the sum of a digit: ");
   
   n=Integer.parseInt(din.readLine());
   r=0;
   s=0;
   
   while(n>0){
    r=n%10;
    s=s+r;
    n=n/10;
   }
   
   System.out.println("The sum of the digit is : " +s);
  } catch(IOException e) {
   System.out.println("Wrong Input");        
  }
  }  
}      
     
Output of sum of digit Program:
Please enter the number to find the sum of a digit: 12345

The sum of the digit is : 15