A Typical Scenario

A more complete example ...

// Base class

class Person {
private:
int
idNum;
string firstName;
string lastName;
public:
void setData(int id, string fn, string ln);
void printData() const;
};

void Person::setData(int id, string first, string last)
{
idNum = id;
lastName = last;
firstName = first;
}

void Person::printData() const
{
cout << "ID: " << idNum << ", Name: " << firstName << " " << lastName << endl;
}

// Derived class

class Customer : public Person {
private:
double balanceDue;
public:
void setBalanceDue(double);
void outputBalanceDue() const;
};

void Customer::setBalanceDue(double bal)
{
balanceDue = bal;
}

void Customer::outputBalanceDue() const
{
cout << "Balance due $" << balanceDue << endl;
}