面向对象C习题参考解答.docx

1、面向对象C 习题参考解答4-8 定义一个Dog类，包含age,weight等属性，以及对这些属性操作的方法。实现并测试这个类。#include using namespace std;class Dogpublic: void setAge(int a) age=a; int getAge() return age; void setWeight(float w) weight=w; float getWeight() return weight; private: int age; float weight;void main() Dog d; d.setAge(3); d.setWeigh

2、t(30); cout小狗：d.getAge()岁，重d.getWeight()斤。endl;4-9 设计并测试一个名为Rectangle的矩形类，其属性为矩形的左下角与右上角两个点的坐标，根据坐标能计算矩形的面积。#include #include using namespace std;class Rectanglepublic: Rectangle(int xx1,int yy1,int xx2,int yy2) x1=xx1; y1=yy1; x2=xx2; y2=yy2; float getArea() return fabs(x2-x1)*fabs(y2-y1); private:

3、 int x1,y1; int x2,y2;void main() Rectangle rec(0,0,10,20); cout矩形面积：rec.getArea()endl;4-11 定义并实现一个矩形类，有长、宽两个属性，由成员函数计算矩形的面积。#include using namespace std;class Rectanglepublic: Rectangle(int l,int w) length=l; width=w; float getArea() return length*width; private: int length; int width;void main() R

4、ectangle rec(10,20); cout矩形面积：rec.getArea()endl;4-13 定义一个Circle类，有数据成员radius（半径），成员函数getArea()，计算圆的面积，构造一个Circle的对象进行测试。#include using namespace std;const float PI=3.1415;class Circlepublic: Circle(float r) radius=r; float getArea() return radius*PI*PI; private: float radius;void main() Circle c(5.5

5、); cout圆的面积：c.getArea()endl;4-20 定义一个复数类Complex，使得下面的代码能够工作。Complex c1(3,5);Complex c2=4.5;c1.add(c2);c1.show();/源程序如下：#include using namespace std;class Complexpublic: Complex(float r=0.0,float i=0.0) real=r; image=i; void add(Complex b) real=real+b.real; image=image+b.image; void show() coutreal+i

6、mageiendl; private: float real; /实部 float image; /虚部;void main() Complex c1(3,5); Complex c2=4.5; /相当于Complex c2(4.5); c1.add(c2); c1.show();5-7 定义一个Cat类，拥有静态数据成员numOfCats,记录Cat的个体数目；静态成员函数getNumOfCats()，读取numOfCats。设计程序测试这个类，体会静态数据成员和静态成员函数的用法。#include using namespace std;class Catpublic: Cat() num

7、OfCats+; Cat() numOfCats-; static int getNumOfCats() return numOfCats; private: static int numOfCats;int Cat:numOfCats=0;void main() cout现在的Cat数量：Cat:getNumOfCats()endl; Cat a; cout现在的Cat数量：a.getNumOfCats()endl; Cat b; cout现在的Cat数量：b.getNumOfCats()endl;5-14 定义Boat与Car两个类，二者都有weight属性，定义二者的一个友元函数getT

8、otalWeight()，计算二者的重量和。#include using namespace std;class Car;class Boatpublic: Boat(float w) weight=w; friend float getTotalWeight(Boat b,Car c);private: float weight;class Carpublic: Car(float w) weight=w; friend float getTotalWeight(Boat b,Car c);private: float weight;float getTotalWeight(Boat b,C

9、ar c) return b.weight+c.weight;void main() Boat boat(3500); Car car(1000); cout船和汽车共重getTotalWeight(boat,car)公斤。endl;7-5 定义一个基类Shape，在此基础上派生出Rectangle和Circle，二者都有getArea()函数计算对象的面积。使用Rectangle类创建一个派生类Square。#include using namespace std;const float PI=3.14;class Shapepublic: Shape(float a,float b=0.0

10、) this-a=a; this-b=b; protected: float a,b;class Rectangle : public Shapepublic: Rectangle(float l,float w):Shape(l,w) float getArea() return a*b; ;class Circle : public Shapepublic: Circle(float r):Shape(r) float getArea() return a*PI*PI; ;class Square : public Rectanglepublic: Square(float l):Rect

11、angle(l,l) float getArea() return a*a; ;void main() Rectangle r(10,20); Circle c(5); Square s(10); cout矩形的面积：r.getArea()endl; cout圆的面积：c.getArea()endl; cout正方形的面积：s.getArea()endl;7-6 定义一个哺乳动物类Mammal，再由此派生出狗类Dog，定义一个Dog类的对象，观察基类与派生类的构造函数和析构函数的调用顺序。#include using namespace std;class Mammalpublic: Mamm

12、al() coutConstructing Mammal.endl; Mammal() coutDesstructing Mammal.endl; ;class Dog : public Mammalpublic: Dog() coutConstructing Dog.endl; Dog() coutDesstructing Dog.endl; ;void main() Dog d;7-8 定义一个Document类，有数据成员name，从Document派生出Book类，增加数据成员pageCount。#include using namespace std;class Documentpu

13、blic: Document(char * n) strcpy(name,n); void show() coutname; private: char name50;class Book : public Documentpublic: Book(char *n,int p):Document(n),pageCount(p) void show() cout书名：; Document:show(); coutendl页数：pageCountendl; private: int pageCount;void main() Book book(C+语言程序设计,529); book.show()

14、;7-10 定义一个Object类，有数据成员weight及相应的操作函数，由此派生出Box类，增加数据成员height和width及相应的操作函数，声明一个Box对象，观察构造函数与析构函数的调用顺序。#include using namespace std;class Objectpublic: Object() coutConstructing Object.endl; Object() coutDestructing Object.endl; void setWeight(int w) weight=w; int getWeight() return weight; private:

15、int weight;class Box : public Objectpublic: Box() coutConstructing Box.endl; Box() coutDestructing Box.endl; void setHeight(int h) height=h; int getHeight() return height; void setWidth(int w) width=w; int getWidth() return width; private: int height; int width;void main() Box box; box.setHeight(5);

16、 box.setWidth(10); box.setWeight(8); cout盒子：高box.getHeight()，宽box.getWidth()，重box.getWeight()endl;8-4#include using namespace std;class Counterpublic: Counter(int ii=0) i=ii; void print() couti=iendl; Counter operator +(int a) Counter temp; temp.i=i+a; return temp; private: int i;void main() Counter

17、 c; c=c+3; c.print(); c=c+5; c.print();8-5#include using namespace std;class Mammalpublic: virtual void speak() coutMammal Speak!endl; ;class Dog:public Mammalpublic: virtual void speak() coutDog Speak!speak();8-7#include using namespace std;class Pointpublic: Point(int x=0,int y=0) X=x; Y=y; void p

18、rint() cout(X,Y)endl; Point& operator+() X+; Y+; return *this; Point operator+(int) Point temp=*this; X+; Y+; return temp; private: int X,Y;void main() Point p; (+p).print(); (p+).print(); (+p).print();仅供个人用于学习、研究；不得用于商业用途。For personal use only in study and research; not for commercial use.Nur fr de

19、n persnlichen fr Studien, Forschung, zu kommerziellen Zwecken verwendet werden.Pour l tude et la recherche uniquement des fins personnelles; pas des fins commerciales. , , . 以下无正文 仅供个人用于学习、研究；不得用于商业用途。For personal use only in study and research; not for commercial use.Nur fr den persnlichen fr Studien, Forschung, zu kommerziellen Zwecken verwendet werden.Pour l tude et la recherche uniquement des fins personnelles; pas des fins commerciales. , , . 以下无正文