Thread: program crashes while printing data from vectors

i have a localstudent and internationalstudent class inherit from student class. read and print are virtual functions. After i have set all the member variables when i wan to print out all the student information, my program crashes. Why and how to fix it?

Code:

int main()
{
    clsUniversityProgram objProgram[3];
    for (int x = 0; x < 3; x++)
    {
        objProgram[x].programInfo();  // prompt user to enter program details and set them accordingly
    }
    vector <clsStudent*> student;
    addStudents(student, objProgram);
    student.front()->print();

    return 0;
}

addStudents function

Code:

void addStudents(vector <clsStudent*>& student, clsUniversityProgram objProgram[])
{
    clsLocalStudent *studentadd;
    studentadd = new clsLocalStudent();
    studentadd->read(objProgram);
    student->push_back(studentadd);
}

read virtual function

Code:

void clsLocalStudent::read(clsUniversityProgram *objProgram)
{
    int program, years, times;
    clsUniversityProgram selectProgram;
    clsDate mDOB;
    double mGPA;
    string studName, accNo, gender;
    float rate, principle;


    setNationality("Local");


    // prompt for student name
    cout << endl << "Student name\t\t: ";
    cin >> studName;
    setName(studName);


    // prompt for student DOB
    cout << endl << "Date of Birth\t\t: ";
    cin >> mDOB;
    setDateOfBirth(mDOB);


    cout << " +===========================+" << endl;
    cout << "  press 1 - for " << objProgram[0].getProgramName()
                        << "\n  press 2 - for " << objProgram[1].getProgramName()
                        << "\n  press 3 - for " << objProgram[2].getProgramName() << endl;
    cout << " +===========================+";
    cout << endl << "Program name\t\t: ";
    cin >> program;


     while (program != 1 && program != 2 && program != 3)
    {
        cout << "Invalid program! Please select key in 1, 2 or 3 only.";
        cin >> program;
    }


    if (program == 1)
    {
        setProgram(&objProgram[0]);
    }


    else if (program == 2)
    {
        setProgram(&objProgram[1]);
    }


    else
    {
        setProgram(&objProgram[2]);
    }


    clsAccount objAccount(accNo,studName,accID,mDOB, accStartDate, principle, rate, years, times);
    setAccounts(objAccount);

    // and setting other information
}

print virtual function

Code:

void clsLocalStudent::print()
{
    cout << "\nStudent Name\t\t\t: " << getName()
        << "\nDate of Birth\t\t\t: " << getDateOfBirth()
        << "\nProgram Name\t\t\t: << getProgram()->getProgramName()
        << "\nAccount Number\t\t: << getAccounts()->getAccountNumber();
}

You fix it by running it in the debugger and waiting for it to crash.

The debugger will catch the exception, and point you at a line of code.
It will also give you a stack trace showing the function call hierarchy at that point. You can move through these stack frames to examine the program state at each function level.

The object of the exercise is to start at the innermost function (where the crash actually occurred), then work your way back towards main(), looking for something which is wrong.
Say for example
- bad input data
- erroneous calculations
- uninitialised data
- subscripts out of range
etc etc.

You can also use the debugger to do this process forwards.
You start by setting a breakpoint at the start of main, and then step your way through the code until you see it doing something you didn't expect.

Originally Posted by jocdrew21

Can I see the .h file too?

you can see whatever the compiler saw at the time that the program was built. gdb is a good command line based debugger that can show you the lines of code as you step through them. visual studio has an outstanding integrated debugger. I often wish GDB was as fast and well integrated as the visual studio debugger. many IDEs like eclipse, netbeans, and code::blocks do a pretty good job of integrating gdb.