C++ Program To Find Sum of Digits of Given Number

Q: Input an integer number. Find and show the sum of digits of given number.

      For example, if given number is 123 then answer will be Sum of digits = 6

      because 1+2+3 = 6.

         

Input Number Add its digits C++ Program

The Actual C++ Code of Add Digits of a given number Program

/*
Program to input a number, then display sum of its digits.
(c) Www.EasyCppProgramming.Blogspot.Com
*/
#include<iostream.h>
#include<conio.h>
#include<math.h>
void main()
{
     int num, temp, sum=0, r, q;
     clrscr();
     cout<<"Enter a number to add its Digits=";
     cin>>num;
     temp = num;
     while ( temp>0 )
     {
       q = temp/10;
       r = temp % 10;
       sum = sum + r;

       temp = q;
     }
     cout<<"\n The sum of digits of given number "<<num<<"  =  "<<sum;
     getch();
     }

Write C++ Program to find sum of digits of given number

The Working of  C++ Code of Add Digits of a given number Program

This program is of reverse number logic.

1. We will divide 123 by 10 and get quotient=12, r = 3
2. add r=3 into sum, so sum=3

3. Now put q =12 into dividend number
4. so divide 12 by 10, quotient=1 and remainder r=2.
5. Add r=2 into sum, so sum will become 5.
6. now put q=1 into dividend number

7. Now divide 1 by 10, quotient=0 and r=1.
8. so add r=1 into sum, and sum becomes 6
9. now put quotient=0 into dividend number called temp variable
10. so that while loop test condition while (temp>0) becomes false and loop terminates.

11. Therefore display the answer sum of digits of number 123 = 6

/*
Program to input a number, then display sum of its digits.
(c) Www.EasyCppProgramming.Blogspot.Com
*/
#include<iostream.h>     // include header files
#include<conio.h>

void main()
{
     int num, temp, sum=0, r, q;
     clrscr();
     cout<<"Enter a number to add its Digits=";
     cin>>num;                 // input number
     temp = num;             // copy number into temp variable
     while ( temp>0 )      // loop while temp is greater than zero
     {
       q = temp/10;      // calculate quotient = temp number / 10, if num is 123 then q=12
       r = temp % 10;  //  calculate remainder r = 123 % 10, r = 3
       sum = sum + r;  // sum = 0 + 3; so last digit 3 of 123 is added in sum variable
                               
       temp = q;      // set next time dividend     temp=12
     }
     cout<<"\n The sum of digits of given number "<<num<<"  =  "<<sum; //sum=6
     getch();
     }