Virtual Function

A Member Function of a Base Class that can be overidden in derived classes, implying Dynamic Polymorphism.

• Virtual designation indicates that we want to look inside the data a pointer owns to see what its type is before calling its function. If a member function is non-virtual and overriden in derived classes, calls to a child stored in the base class will execute the non-virtual base class function, not the child function.

Language Specific Details

• In C++, member functions are non-virtual by default, and must be opted-in to through the virtual keyword
• In Java, all non-static non-final member “methods” are virtual by default, you must opt-out through the final keyword