circle5.cpp

《c＋＋大学教程》源码

// Fig. 9.28: circle5.cpp
// Circle5 class member-function definitions.
#include <iostream>  

using std::cout;
using std::endl;

#include "circle5.h"   // Circle5 class definition

// default constructor
Circle5::Circle5( int xValue, int yValue, double radiusValue )
   : Point4( xValue, yValue )  // call base-class constructor
{
   setRadius( radiusValue );

   cout << "Circle5 constructor: ";
   print();
   cout << endl;

} // end Circle5 constructor

// destructor
Circle5::~Circle5()
{
   cout << "Circle5 destructor: ";
   print();
   cout << endl;

} // end Circle5 destructor

// set radius 
void Circle5::setRadius( double radiusValue )
{
   radius = ( radiusValue < 0.0 ? 0.0 : radiusValue );

} // end function setRadius

// return radius 
double Circle5::getRadius() const
{
   return radius;

} // end function getRadius

// calculate and return diameter
double Circle5::getDiameter() const
{
   return 2 * getRadius();

} // end function getDiameter

// calculate and return circumference
double Circle5::getCircumference() const
{
   return 3.14159 * getDiameter();

} // end function getCircumference

// calculate and return area
double Circle5::getArea() const
{
   return 3.14159 * getRadius() * getRadius();

} // end function getArea

// output Circle5 object
void Circle5::print() const
{
   cout << "Center = ";
   Point4::print();      // invoke Point4's print function
   cout << "; Radius = " << getRadius();

} // end function print

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