$14\mathrm{.}3($The Circle class$)$

Implement $($add$)$ the relational operators $(<,<=,==,!=,>,>=)$ in the Circle class in Listing $10\mathrm{.}9,$ provided below for your convenience, to order the Circle objects according to their radii.

#ifndef CIRCLE$\_$H

#define CIRCLE$\_$H

class Circle

$\{$

public:

Circle$()$;

Circle$($double$)$;

double getArea$()$ const;

double getRadius$()$ const;

void setRadius$($double$)$;

static int getNumberOfObjects$()$;

private:

double radius;

static int numberOfObjects;

$\}$;

#endif

IMPORTANT:

Students regularly submit the Circle.h without implementing the relational operators. Which is basically the listing $10\mathrm{.}10.$ Please understand, you should use listing $10\mathrm{.}10,$ as the base and add the additional methods. The final submission includes the Circle.h$,$ Circle.cpp$,$ and the test program.

#include "Circle.h$"$

int Circle::numberOfObjects $=0$;

$//$ Construct a circle object

Circle::Circle$()$

$\{$

radius $=1$;

numberOfObjects$++$;

$\}$

$//$ Construct a circle object

Circle::Circle$($double newRadius$)$

$\{$

radius $=$ newRadius;

numberOfObjects$++$;

$\}$

$//$ Return the area of this circle

double Circle::getArea$()$ const

$\{$

return radius $*$ radius $*3\mathrm{.}14159$;

$\}$

$//$ Return the radius of this circle

double Circle::getRadius$()$ const

$\{$

return radius;

$\}$

$//$ Set a new radius

void Circle::setRadius$($double newRadius$)$

$\{$

radius $=($newRadius $>=0)?$ newRadius : $0$;

$\}$

$//$ Return the number of circle objects

int Circle::getNumberOfObjects$()$

$\{$

return numberOfObjects;

$\}$