Teach Yourself Borland C++ in 14 Days - portal

100 Day 4
protected:
void StartupProcedure();
private:
void StartElectricalSystem();
void StartEngine();
int currentGear;
bool started;
int speed;
};
Notice that the constructor does not have a return type. A constructor cannot return a value,
so no return type is specified. If you try to add a return type to the constructor declaration,
you will get a compiler error.
A class can have more than one constructor. This is possible through function overloading,
which I discussed on Day 3, “Up to Your Neck in C++.” For instance, a class might have a
constructor that takes no parameters (a default constructor) and a constructor that takes one
or more parameters in order to initialize data members to certain values. For example, let’s
say you have a class called Rect that encapsulates a rectangle (rectangles are frequently used
in Windows programming). This class could have several constructors. It could have a default
constructor that sets all the data members to 0, and another constructor that allows you to
set the class’s data members through the constructor. First, let’s take a look at how the class
declaration might look:
class Rect {
public:
Rect();
Rect(int _left, int _top, int _bottom, int _right);
int GetWidth();
int GetHeight();
void SetRect(int _left, int _top, int _bottom, int _right);
private:
int left;
int top;
int bottom;
int right;
};
The definitions for the constructors, then, would look something like this:
Rect::Rect()
{
left = 0;
top = 0;
bottom = 0;
right = 0;
}
Rect::Rect(int _left, int _top, int _bottom, int _right)
{
left = _left;
top = _top;
bottom = _bottom;
right = _right;
}