In the previous example, we kept the struct very simple. Since the struct didn't have any member functions, we only needed to worry about when non-member functions want to modify the data. However, object-oriented programming suggests that we shouldn't have data be public. Instead, all data should be private and accessed through public member functions. Let's look at a very simple example to understand this concept:
class Simple { public: Simple(void) { m_data = 0; } void SetData(int data) { m_data = data; } int GetData(void) { return m_data; } private: int m_data; }; int main(void) { Simple s; const Simple cs; s.SetData(10); //Works as Expected int value = s.GetData();//Works as Expected cs.SetData(10); //Error ...
