PLEASE HELP! I do not undertand why I get this output

[Nata]

#include <iostream>
using namespace std;

int main()
{
int a;
int b = 0;

cout << " Enter a number : ";
cin >> a;

while ( a > 0 ) {
b =b+ a % 10;
a= a/ 10;

}

cout << "Sum = " << b;

return 0;
}


this code calculates sum of the digits of a number.
Even though I know it works I have a question that I cannot understand

for example if I write in cin that the number is 14.
than b=0+4=4 and a=14/10=1
and if the sum is b and b= 5, how is that my answer is still 5?

[Mats]

and if the sum is b and b= 5, how is that my answer is still 5?

Because b is the answer. b is just a running total of the digit sum. This is what happens when you put in 14.

b = 0;
b = b + a % 10 | 0 = 0 + Remainder of (14 / 10) | 0 = 0 + 4
b = b + a % 10 | 4 = 4 + Remainder of (10 / 10) | 4 = 4 + 1
b = 5
cout << b;

[Nata]

Thank you now I get everything you are the best:)) I am just beginning to study c++, so I have really big problems understanding some of it! thanks!!

[Nata]

so that means when I put 121

b=0
b=b+a%10
0=0+remainder of (121/10)
0=0+1
b=b+a%10
b=b+remainder of (120/10)
1=1+12=13

but the sum actually should be 4. So why is it 13?

[Mats]

121

b = b + Remainder of 121 / 10 | b = b + 1
b = b + Remainder of 12 / 10 | b = b + 2
b = b + remainder of 1 / 10 | b = b + 1
b = 4

You can never have a remainder > 10 if you are dividing by 10!

If you want to see program output, just put cout << a << "\n"; before the equations.

cout << a << "\n";
b =b+ a % 10;
a= a/ 10;

[Nata]

okay I get it now :)))))))) thanks!!!