C++面向对象程序设计第六章课后习题答案

1、第六章课后习题答案（第二版谭浩强）1:/xt6-1/cpp#include<iostream>/如用VC+应改为：#include<iosttram.h>usingnamespacestd;/如用VC+5取消此行#include"cylinder.h"#include"point.cpp"#include"circle.cpp"#include"cylinder.cpp"intmain()Cylindercy1(3.5,6.4,5.2,10);cout<<"norigi

2、nalcylinder:nx="<<cy1.getX()<<",y="<<cy1.getY()<<",r="<<cy1.getRadius()<<",h="<<cy1.getHeight()<<"narea="<<cy1.area()<<",volume="<<cy1.volume()<<endl;cy1.setHeight(15);cy1.s

3、etRadius(7.5);cy1.setPoint(5,5);cout<<"nnewcylinder:n"<<cy1;Point&pRef=cy1;cout<<"npRefasapoint:"<<pRef;Circle&cRef=cy1;cout<<"ncRefasaCircle:"<<cRef;return0;3:解法一#include<iostream>usingnamespacestd;classPointpublic:Poin

4、t(floata,floatb):x(a),y(b)Point()cout<<"executingPointdestructor"<<endl;private:floatx;floaty;classCircle:publicPointpublic:Circle(floata,floatb,floatr):Point(a,b),radius(r)Circle()cout<<"executingCircledestructor"<<endl;private:floatradius;intmain()Point*

5、p=newCircle(2.5,1.8,4.5);deletep;return0;3：解法二#include<iostream>usingnamespacestd;classPointpublic:Point(floata,floatb):x(a),y(b)Point()cout<<"executingPointdestructor"<<endl;private:floatx;floaty;classCircle:publicPointpublic:Circle(inta,intb,intr):Point(a,b),radius(r)Ci

6、rcle()cout<<"executingCircledestructor"<<endl;private:floatradius;intmain()Point*p=newCircle(2.5,1.8,4.5);Circle*pt=newCircle(2.5,1.8,4.5);deletept;return0;3：解法三#include<iostream>usingnamespacestd;classPointpublic:Point(floata,floatb):x(a),y(b)virtualPoint()cout<<&q

7、uot;executingPointdestructor"<<endl;private:floatx;floaty;classCircle:publicPointpublic:Circle(floata,floatb,floatr):Point(a,b),radius(r)destructor"<<endl;virtualCircle()cout<<"executingCircleprivate:floatradius;voidmain()Point*p=newCircle(2.5,1.8,4.5);deletep;4：#inc

8、lude<iostream>usingnamespacestd;/定义抽象基类ShapeclassShapepublic:virtualdoublearea()const=0;/纯虚函数;/定义Circle类classCircle:publicShapepublic:Circle(doubler):radius(r)/结构函数virtualdoublearea()constreturn3.14159*radius*radius;/定义虚函数protected:doubleradius;/半径;/定义Rectangle类classRectangle:publicShapepublic

9、:Rectangle(doublew,doubleh):width(w),height(h)/结构函数virtualdoublearea()constreturnwidth*height;/定义虚函数protected:doublewidth,height;/宽与高;classTriangle:publicShapepublic:Triangle(doublew,doubleh):width(w),height(h)/结构函数virtualdoublearea()constreturn0.5*width*height;/定义虚函数protected:doublewidth,height;/宽与

10、高;/输出面积的函数voidprintArea(constShape&s)cout<<s.area()<<endl;/输出s的面积intmain()Circlecircle(12.6);/建立Circle类对象circlecout<<"areaofcircle="printArea(circle);/输出circle的面积Rectanglerectangle(4.5,8.4);/建立Rectangle类对象rectanglecout<<"areaofrectangle="printArea(rect

11、angle);/输出rectangle的面积Triangletriangle(4.5,8.4);/建立Triangle类对象cout<<"areaoftriangle="printArea(triangle);/输出 triangle 的面积return0;5：#include<iostream>usingnamespacestd;/定义抽象基类ShapeclassShapepublic:virtualdoublearea()const=0;/纯虚函数;/定义Circle(圆形)类classCircle:publicShaper):radius(r)

12、public:Circle(double/结构函数virtualdoublearea()constreturn3.14159*radius*radius;/定义虚函数protected:doubleradius;/半径;/定义Square(正方形)类classSquare:publicShapepublic:Square(doubles):side(s)/结构函数virtualdoublearea()constreturnside*side;/定义虚函数protected:doubleside;/定义Rectangle(矩形)类classRectangle:publicShapepublic:

13、Rectangle(double/结构函数w,doubleh):width(w),height(h)virtualdoublearea()constreturnwidth*height;/定义虚函数protected:double/宽与高;/定义Trapezoid(梯形)类classTrapezoid:publicShapepublic:Trapezoid(doubleh):top(t),bottom(t),height(h)/t,double结构函数width,height;b,doublevirtualdouble0.5*(top+bottom)*height;/area()const定义

14、虚函数returnprotected:doubletop,bottom,height;/上底、下底与高;/定义Triangle(三角形)类classTriangle:publicShapepublic:Triangle(doublew,doubleh):width(w),height(h)/结构函数virtualdoublearea()constreturn0.5*width*height;/定义虚函数protected:doublewidth,height;/宽与高;intmain()Circlecircle(12.6);/建立Circle类对象circleSquare/建立Square类对象squaresquare(3.5);Rectanglerectangle(4.5,8.4);/建立Rectangle类对象rectangleTrapezoidtrapezoid(2.0,4.5,3.2);/建立Trapezoid类对象trapezoidTriangletriangle(4.5,8.4);/建立Triangle类对象Shape*pt5=&circle,&square,&rectangle,&trapezoid,&t