C++ sum of digits of each element in a column - c++

Question

I am new to C++, trying to import dates into a program, adding up digits of day, month, year resp and writing back to txt.
input data
sl.no name day month year
1 Rob 15 05 2019
2 Tim 12 06 2002
Desired output data in txt
sl.no name day month year
1 Rob 6 5 3
2 Tim 3 6 4
I have been able to import data from a txt file and also add the digits in day but it does not repeat forward. what am i doing wrong ?
sample code
#include <iostream>
#include <fstream>
using namespace std;
int main()
{
ifstream theFile("data.txt");
int id,day,month,year,daysum=0,monthsum=0, yearsum=0;
string name;
while (theFile >> id >> name >> day >> month >> year)
{
cout << id << ", "<< name <<", "<< day<<", "<<month <<", "<< year<<","<< endl;
}
while (day > 0)
{
daysum = daysum + (day % 10);
day = day / 10;
cout << daysum << endl;
}

Answer 1

I am no expert . but have been in your spot a few months ago.. break down the problem into smaller steps..
My approach..
Pseudo Code:
Ditch the header
Create a function for adding the digits
Read data from file
Use a loop to run through each element of the every column and use the function created
Store results in a variable
Output variable to a new text file
comment if there is a specific area where you are stuck..
Try this to reduce it to single digits.. knit to other parts of your code..
#include <iostream>
using namespace std;
int main()
{
long long num;
cout << "Enter a number: ";
cin >> num;
int sum = 0;
while (1)
{
sum += (num % 10);
num /= 10;
if (0 == num)
{
if (sum > 9)
{
num = sum;
sum = 0;
}
else
{
cout << "Answer: ";
cout << sum << endl;
return 0;
}
}
};
return 0;
}

Answer 2

you are reading the file and data wrong,
you need to discard the header (sl.no name day month year)
and then accumulate the daysum while reading the file progressively one row after the other until the end...