Selecting text between two commas C++?

Question

C++ / C#

There is an input string with two commas. I find the positions of two commas and divide into 3 substrings by commas, but the substring between two commas is not determined correctly.

#include <iostream>
#include <string>
using namespace std;
string stroke;
int n;

int main()
{

  cin >> n;
  if (n > 10000 || n < 1) {
    return -1;
  }
  cin.ignore();
  for (int i = 1; i <= n; i++) {
    getline(cin, stroke);
    cout <<"string: "<< stroke << endl;
    //деление строки на персон :
    short zap1 = stroke.find(",");
    short zap2 = stroke.find(",",zap1+1);
    cout << "zap2 : " << zap2 << endl;
    string dad, mom, son;
    dad = stroke.substr(0, zap1);
    mom = stroke.substr(zap1 + 1, zap2);
    son = stroke.substr(zap2 + 1);
    cout << "son : "<<son << "  moth : "<<mom<<"  dad : " << dad <<endl;
      

  }
  
}

I get a string from the first comma to the end, although everything else is defined correctly.

Answer 1

Because the second parameter in substr is not the end position, but the number of characters. Feel the difference.