Modularization in C++

Question

I am currently working on a (very very basic) program that is a tutorial for programming( ironic given my knowledge, I know). I was instructed to modularize my code so that each unit is in its own module. I'm guessing that means adding headers? I'm working with Visual Studios, if that helps at all. I've included my code below to help my bad explanation make sense. Thanks for any help you can provide!

#include <iostream>
#include <iomanip>
#include <string>
using namespace std;

int Total;
int ans;

class Question
{
private:
    string Question_Text;
    string Answer_one;
    string Answer_two;
    string Answer_three;

    int Correct_Answer;
    int Question_Score;

public:
    void setValues(string, string, string, string, int, int);
    void askQuestion();
};

int main()
{
    string username = "";
    char choice=' ';
    char c;
    int x = 4;
    int y = 5;
    int z = x + y;


    //welcome message
    cout << "Hello user, please enter your name:";
    cin >> username;
    cout << "Welcome to the programming tutorial " << username << "." << endl;

    //menu selection
    while(choice != '5')
    {
        cout << "What would you like to do? (Unit 1 - Declaring Variables (1), Unit 2 - Input/ Output (2), Unit 3 - Conditionals (3), Quizzes (4) or Exit (5))";
        cin >> choice;
        if (choice == '1')
        {
            cout << "We will begin with defining variables. The first step to doing this is choosing which datatype your variable is.\n";
            cout << "The following are a few of the common datatypes used in programming.\n";
            cout << "Character ==> char\n";
            cout << "Integer ==> int, long, double\n";
            cout << "Boolean ==> bool\n";
            cout << endl;
            cout << "When declaring a variable, you must put its datatype before the variable name.\n";
            cout << "An example of this would be if we wanted to declare the value of x as 4.\n";
            cout << "We would write this as: \n";
            cout << "int x = 4\n";
            cout << "The program will now use the value 4 for the variable name 'x'\n";
            cout << endl;
            cout << "Now let's assume we assigned the value of 5 to the variable 'y'\n";
            cout << "If we wanted to add x and y and assign the sum to the variable 'z', we would write:\n";
            cout << "int z = x + y\n";
            cout << "Now when we use the variable 'z' in our program, it will perform the calculation given x=4 and y=5 and declare 9 as the value of the variable 'z'.\n";
            cout << "To test our code, we would write: " << endl;
            cout << "cout<<'x + y'<< z << endl; \n";
            cout << "If written correctly, it will display as: \n";
            cout << "x + y = " << z << "." << endl;

        }
        if (choice == '2')
        {
            cout << "Now that we understand the basics of declaring variables, let's discuss displaying, or output of, information to a user.\n";
            cout << "If you wanted to display a welcome message, for example, you would type:\n";
            cout << "cout << 'Welcome';\n";
            cout << "The line of code would start with 'cout' followed by two less than signs and then the message you wish to display in quotes.\n";
            cout << "Using this, you can ask the user for input.\n";
            cout << "Enter c to continue...";
            cin >> c;
            cout << "Let's say we have a program that flips a coin. You may want to ask the user how many times to flip the coin.\n";
            cout << "Assuming we previously declared this amount variable as 'int timesFlipped', we would 'cout' our question and the next line would read:\n";
            cout << "cin>> timesFlipped; \n";
            cout << "This will store the users input for the variable 'timesFlipped'\n";
            cout << "You almost always end a line of code with a semi colon." << endl;
        }
        if (choice == '3')
        {
            cout << "This unit will cover conditional expressions." << endl;
        }
        if (choice == '4')
        {
            string Question_Text;
            string Answer_one;
            string Answer_two;
            string Answer_three;

            int Correct_Answer;
            int Question_Score;
            Question q1;
            Question q2;
            Question q3;


            cout << username << ", you have chosen to take a quiz." << endl << endl;
            int ans, score = 0;
            cout << "Unit One Quiz - Variables " << endl << endl;

            q1.setValues("How would you declare the value of 'x' as 12? ",
                "x=12()",
                "x==12()",
                "x=12;()",
                3,
                1);
            q2.setValues("What do you need to put before a variable when declaring it?",
                "a name()",
                "a value()",
                "a datatype()",
                3,
                1);
            q3.setValues("Which data type would you use for a number that includes a decimal value?",
                "int()",
                "double()",
                "float()",
                2,
                1);

            q1.askQuestion();
            q2.askQuestion();
            q3.askQuestion();

            cout << "Your score out of a possible 3 is " << Total << endl;

        }
        if (choice == 'E')
        {
            cout << "Have a good day!";
            break;
        }
    }


    system("pause");
}

void Question::setValues(string q, string a1, string a2, string a3, int ca, int pa)
{

    Question_Text = q;
    Answer_one = a1;
    Answer_two = a2;
    Answer_three = a3;
    Correct_Answer = ca;
    Question_Score = pa;
}

void Question::askQuestion()
{

    cout << endl;
    cout << Question_Text << endl;
    cout << "1. " << Answer_one << endl;
    cout << "2. " << Answer_two << endl;
    cout << "3. " << Answer_three << endl << endl;
    cout << "Please enter your answer: " << endl;
    cin >> ans;

    if (ans == Correct_Answer)
    {
        cout << "That is correct!" << endl;
        Total = Total + Question_Score;
    }
    else
    {
        cout << "Sorry, that is incorrect" << endl;
        cout << "The correct answer was " << Correct_Answer << endl;
    }
}

Answer 1

I'm guessing that means adding headers?

That's pretty much the idea.

In your case, you may want to:

• Create a header name Question.h that includes the declaration of class Question.
• Create a source file name Question.cpp and move the class definition there, ie all functions like void Question::askQuestion() etc.
• Create a test file name test.cpp to put your main function, and remember to include the Question.h

As you are using Visual Studio, you can create a Project in advance then add all those files before compiling/building.