Operator Overloading

scuzzo · #1 10-Apr-2009, 09:17

I'm sinking fast and need some help. I'm taking my second semester of c++ programming and for this assignment I need to create a class and use overloaded operators to input and output and ex.
Define and implement a class named Rectangle. Its partial declaration is given below:

CPP / C++ / C Code:

class Rectangle
{
private: 
	Point p;			// top-left corner of the rectangle
	float width, height;	// width and height of the rectangle

public:
	// constructors
	Rectangle();	// default values: p=(0,0) width=1 height=1
	Rectangle(Point pt, float w, float h);

// --------------------------------------------
	// input and output
// --------------------------------------------
// Implement >> and << here as non-member functions. 
// Operator << should plot(draw) the rectangle.  
// Operator >> should prompt for user input of the x-y
// coordinates of the top-left corner, width and height of a 
// rectangle.

// --------------------------------------------
	// *: scale the rectangle
// --------------------------------------------
// Implement * as a non-member function
// Implement *= as a member function.

// --------------------------------------------
	// +: move the rectangle to another location
// --------------------------------------------
// Implement + as a non-member function
// Implement += as a member function.

// --------------------------------------------
// Compare two rectangles
// --------------------------------------------
// Implement < and == operators as non-member functions, 
// where R1<R2 is true if R1 is contained in R2, 
// R1==R2 is true if R1 and R2 overlaps
};

Write a program to test your class. The program should provide a menu to a user to read, plot, scale, and move a rectangle, as well as enter another rectangle for comparison. The following is an example when running the program.

I am so very very lost. Can anyone suggest any resource that will go VERY slowly or give me some pointers on where to start.

fakepoo · #2 10-Apr-2009, 10:18

Here is how you would apply the constructors and the scale:

CPP / C++ / C Code:

// Rectagle.h

class Point
{
public:
	int X;
	int Y;

	Point& operator=(const Point& p)
	{
		if(this != &p)
		{
			X = p.X;
			Y = p.Y;
		}

		return *this;
	}
};


class Rectangle
{
private:
	Point p;
	float width, height;

public:
	// Constructors
	Rectangle();
	Rectangle(Point pt, float w, float h);

	// Member operators
	Rectangle& operator*=(float scale);

	// Non-member operators
        // NOTE: Declare as a "friend" so that it can access Rectangle's private members.
	friend Rectangle operator*(const Rectangle& rectangle, float scale);
        
};

CPP / C++ / C Code:

// Rectangle.cpp

#include "Rectangle.h"

// Constructor
Rectangle::Rectangle()
{
	p.X = 0;
	p.Y = 0;
	width = 1.0;
	height = 1.0;
}

// Constructor
Rectangle::Rectangle(Point pt, float w, float h)
{
	p.X = pt.X;
	p.Y = pt.Y;
	width = w;
	height = h;
}

// Non-member scale operator
Rectangle operator*(const Rectangle& rectangle, float scale)
{
	return Rectangle(rectangle.p, rectangle.width*scale, rectangle.height*scale);
}

// Member scale operator
Rectangle& Rectangle::operator*=(float scale)
{
	width *= scale;
	height *= scale;
	return *this;
}

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Operator Overloading

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