Classes—
the full enchilada
Chapter 20
Agenda
Review 
Constructor functions
Accessor functions
Modifier functions
input/output functions
Summary
Review--Modeling a Balloon in C++
class Balloon
{
public:
void initialize(int initRad);
void inflate(int howMuch);
void pop( );
Member Functions
void display();
private:
int radius;
};
Member Data
Review--You can use the public
functions defined for the class
Balloon bal;
bal.initialize(5);
bal.inflate(15);
bal.pop();
Review--Implement the initialize
and inflate functions
void Balloon::initialize(int initRad)
{
This says it is a
radius = initRad;
member function of
Class Balloon
}
void Balloon::inflate(int howMuch)
{
radius = radius + howMuch;
Notice how the
}
parameter modifies
the member data
A ‘client’ program is one that uses a class
int main()
{
Balloon myBalloon;
myBalloon.initialize(3);
cout<<"myBalloon currently has Radius ";
myBalloon.display();
cout<<"\nInflating myBalloon by 8 \n";
myBalloon.inflate(8);
cout<<"Now myBalloon has Radius ";
myBalloon.display();
cout<<"\nPopping myBalloon \n";
myBalloon.pop();
cout<<"myBalloon currently has Radius ";
myBalloon.display();
}
Agenda
Review
Constructor functions 
Accessor functions
Modifier functions
input/output functions
Summary
Fully defined Balloon class in C++
class Balloon
{
public:
// constructor functions
Balloon( );
//
Balloon(int initRad);
// accessor functions
float volume( ) const;
change radius
int getRadius( ) const;
default constructor
// explicit constructor
// const means function can’t
// modifier functions
void inflate(int howMuch);
void pop( );
void setRadius(int r);
…continued
Fully defined Balloon class in C++
…continued
// input/output functions
void display(ostream &out);
void input(istream &in);
private:
int radius;
};
// overloaded operators
ostream& operator<<( ostream& out, Balloon b);
istream& operator>>( istream& in, Balloon &b);
bool operator==( Balloon b1, Balloon b2);