Problem with calling a function with another function (both within classes). No error codes C++

Question

class DatingSim
{
public:
    string userName;
    int userAge;
    int day1Place;
    string places[4] = { "Coffee Shop", " Duck Pond", "Club" , "Class"};
    string dayOneA = "W E L C O M E  T O  D A T I N G  G A M E";


    void slowPrint(string str, int time)
    {
        for (size_t i = 0; i != str.size(); ++i) 
        {
            cout << str[i];
            Sleep(time);
        }
    }
    void dayOne();

void DatingSim::dayOne()
{

    slowPrint(dayOneA, 250);
    cout << endl;

... other code (just cout stuff shouldn't be a problem)
}

int main()
{
    DatingSim NEWGAME;
    NEWGAME.dayOne();

    return 0;
}

So previously instead of a string for the slowprint function parameter I was using a string array but it wasn't working so I switched to just string and it didn't work. I tested it and it works when it's not within a class together. Should I not use a class? I'm creating a little game and I'd rather be able to use a class. No error messages just says FAILED when I try to run.

Answer 1

As suggested, you need to flush the output stream after each letter, otherwise you'll see the entire string printed out at the end.

#include <chrono>
#include <iostream>
#include <string>
#include <thread>

using namespace std;

class DatingSim {
public:
    string userName;
    int userAge;
    int day1Place;
    string places[4] = { "Coffee Shop", " Duck Pond", "Club" , "Class"};
    string dayOneA = "W E L C O M E  T O  D A T I N G  G A M E";

    void slowPrint(string str, int time)
    {
        for (size_t i = 0; i != str.size(); ++i) 
        {
            cout << str[i] << flush;
            this_thread::sleep_for(chrono::milliseconds(time));
        }
    }

    void dayOne()
    {
        slowPrint(dayOneA, 250);
        cout << endl;
    }
};

int main()
{
    DatingSim NEWGAME;
    NEWGAME.dayOne();
    return 0;
}