class declaration in header file c++ example
class Date
{
private:
    int m_year;
    int m_month;
    int m_day;
public:
    Date(int year, int month, int day)
    {
        setDate(year, month, day);
    }
    void setDate(int year, int month, int day)
    {
        m_year = year;
        m_month = month;
        m_day = day;
    }
    int getYear() { return m_year; }
    int getMonth() { return m_month; }
    int getDay()  { return m_day; }
};