# Programming Shortcut

## Monday, February 4, 2019

### Java program to perform sum of digits until single digit is obtained

Hello Friends!
Today will discuss do while loop with an example, how to make a program in java by do-while loop, do while loop in java program an example with explanation.
Write a program in java to find the sum of digits of a number until the sum is reduced to 1 digit.
For example:
The number is 538769.
Then 5+3+8+7+6+9=38
3+8=11
11=2

### Finding sum of digits of a number until sum becomes single digit java program

import java.util.Scanner;
public class do_while {
public static void main(String[] args){
long num,dig,sum;
Scanner in =new Scanner(System.in);
System.out.print("Enter a number :");
num=in.nextLong();
System.out.println("");
System.out.print(num);
do{
sum = 0;
while(num!=0)
{
dig=num%10;
sum+=dig;
num/=10;
}
System.out.print("->"+sum);
num=sum;
}while(num/10!=0);
}
}
Output: Enter a number : 538769
538769->38->11->2

Explanation :

do{
/* 1: program code */
}while(num/10!=0);
The Above Condition is not exited while a number is more than one digit.

/* 1: program code */
while(num!=0)
{
dig=num%10;
sum+=dig;
num/=10;
}
Here we use program code to find a sum of digit then the given program exapmle is for "Sum of digits of a number until the sum is reduced to 1 digit"