Question

JAVA PLEASE

Write a recursive function that does the following:

Given a number, add all the digits and display the sum.

Example:

​​The sum of the number 5432 would be 14.

o Do not use the static modifier. No global variables. Your program should implement a non-tail recursive algorithm. In other words, it should do something as it moves towards the base case, the tail, and also do something as it comes back from the tail to the beginning.

o The input is going to be received as a single integer from the user, in the main function. The input will not be more than four digits long (no validation necessary).

Answer 1

//T estDigitSum.java

import java.util.Scanner;
public class TestDigitSum{
   //recursive method for sum of digits in num
   public int digitSum(int num){
       int sum=0;
       sum = num % 10;
       if(num == 0)
           return 0;
       else
           return sum + digitSum(num / 10);
   }
   //main method
   public static void main(String[] args){
       int count=0,num;
       Scanner read = new Scanner(System.in);   //for reading inputs
       System.out.print("number for sum of digits:");
       num = read.nextInt();   //reading number from user
       //object creation
       TestDigitSum ds = new TestDigitSum();
       int dSum = ds.digitSum(num);   //storing medthod return value
       System.out.println("Digit Sum:"+dSum);   //displaying result
   }
}