================
Virtual Function
================

--------
Examples
--------

C++
===

.. code-block:: cpp

  Student * p = new Student();
  p->aboutMe();

  Person * p = new Student();
  p->aboutMe();

  class Person {
    ...
    virtual void aboutMe() {
      cout << "I am a person.";
    }
  };

  class Student : public Person {
    public:
    void aboutMe() {
      cout << "I am a student.";
    }
  };

.. code-block:: cpp

  class Person {
    int id;
    char name[NAME_SIZE];
    public:
    virtual void aboutMe() {
      cout << "I am a person." << endl;
    }
    virtual bool addCourse(string s) = 0;
  };

  class Student : public Person {
    public:
    void aboutMe() {
      cout << "I am a student." << endl;
    }

    bool addCourse(string s) {
      cout << "Added course " << s << " to student." << endl;
      return true;
    }
  };

  int main() {
    Person * p = new Student();
    p->aboutMe();
    p->addCourse("history");
    delete p;
  }