C++ Member Functions: Methods to Implement Class Behavior

In C++, member functions serve as the behavioral interface of a class, encapsulating together with member variables within the class (e.g., the `greet()` function of a `Person` class), and determining the operations of objects. They can be defined either directly inside the class (commonly used) or outside the class (requiring the scope to be specified with `ClassName::`). Member functions access member variables directly through the implicit `this` pointer (which points to the calling object), where `this->name` is equivalent to `name`. They are invoked via an object (`objectName.functionName()`) or through pointers/references (`->`). Special member functions include the constructor (initializing objects, named identically to the class) and the destructor (cleaning up resources, starting with `~`). Access permissions are divided into `public` (external interface), `private` (only accessible within the class), and `protected` (accessible to subclasses), used for encapsulating details. Member functions are the core of a class, encapsulating attributes and behaviors, binding objects via `this`, managing the object lifecycle, and implementing functionalities.