How can member functions access the data members of a class?

Member functions can access the data members of a class directly within the scope of that class. When you define a member function, it operates within the context of an instance of that class, meaning it can directly interact with the class's data members without needing any intermediary means, such as pointers or external references.

This direct access is fundamental to object-oriented programming in C++, as it allows encapsulation. The member function can manipulate and access the data members to carry out its intended functionality, ensuring that the integrity of the object's state is maintained.

For instance, when you call a member function on an object, that function can seamlessly look up and modify the attributes of the object it belongs to. This is essential for maintaining cohesion within the class, allowing the data and methods to work together harmoniously.

In contrast, using global variables would make data sharing less structured and lead to potential conflicts and unintentional misuse of data. Static methods, while capable of being called on the class itself without an instance, do not have direct access to instance-specific data members. Also, while pointers can be used to access data members, they involve an additional layer of indirection, which is unnecessary when member functions can directly access the data members of their own class.