C++ Program to find the sum of digits of a number

November 16, 2021

Program to find the sum of digits of a number

Here we will discuss how to find the sum of digits of a number in C++ programming language.

To find the sum of digits in a number we will use loops along with two arithmetic operators, ‘/ ’ and ‘% ’.
Eg: number =12345
Sum of digit of number=1+2+3+4+5
Ans= 15

sum of digits of a number in cpp

Algorithm:-

  • Take int number as input and store it in num
  • To extract digits we have to use modulus operator (num%10) , this will give us digit at unit place
  • For subsequent digits we have to update num as num=num/10, so unit digit will get removed from number
  • Initialize sum=0
  •  A do while loop is started
    • Value of sum is incremented by remainder of num divide by 10 i.e. num % 10

                                 sum+=num%10; 

    • Divide num by 10 and store result in num itself   

                                num=num/10;

    • Do this until num is not equal to 0

                                while(num!=0);

  • sum is printed which is the output
C++ Program to find the sum of digits of a number

C++ Code

//C++ Program
//Sum of digits in a number
#include<iostream>
using namespace std;
int main()
{
    int num,sum=0;
    cout<<"Enter any num : ";
    //user input
    cin>>num;

    //loop to find sum of digits
    do
    {
        sum+=num%10;
        num=num/10;

    }while(num!=0);

        //output

    cout<<"\nSum of digits in given integer is: "<<sum;
    return 0;

}

Output

Enter any num : 12345
Sum of digits in given integer is: 15
PrepInsta C Cpp Course
List of Top 100 Codes