李爱华程磊 面向对象程序设计课后答案.docx

1、李爱华程磊 面向对象程序设计课后答案第二章2-4#include using namespace std;Add(int a,int b);int main()int x,y,sum;coutxy;sum = add(x,y);cout x+y=sumendl;Add(int a,int b)return a+b;2-5(1)this is a C+ program.(2)x=50.6 y=10 z=Ax=216.34 y=10 z=Ax=216.34 y=2 z=Ax=216.34 y=2 z=E(3)x y z500 1000 0500 1500 1500500 200 15002-6#i

2、nclude using namespace std; int main() int *p,*init; int countp=0; int countn=0; p = new int20; init = p; for(int i=0;i*p; p+; p = p-20; for( i=0;i0) countp+; if(*p0) countn+; cout*p ; p+; cout正数有:countpendl; cout负数有:countnendl; p = init;delete p;return 0;2-7不做要求#include /#include using namespace st

3、d;void checkagescore(string name,int age) if (name = exit) throw name; if(age50) throw age; int main() string name; int age; for(int i=0 ;iage ; try checkagescore(name,age); catch( string) coutexception :name is exitendl; continue; catch(int) coutexception :age is not properendl; continue; coutname:

4、name age :ageendl; return 0; 第三章3-1（1）A （2）C （3）B （4）C （5）C（6）B （7）B （8）C （9）C3-7（1）main()函数中 p1.age = 30;语句是错误的。age 是类的私有成员（2）构造函数应当给常数据成员和引用成员初始化，将构造函数改为：A(int a1,int b1):a(a1),b(b1)或A(int a1 ):a(a1),b(a)再将main中的A a(1,2); 改为A a(1);(3)(1)在Test 类中添加语句：void print();void Print() coutx-y=x-yendl;改为void

5、 Test:Print() coutx-y=x-yendl;main函数中Init(38,15);改为：A.Init(38,15);Print();改为：A.Print(); 3-8(1)Constructing AConstructing BDestructing BDestructing A(2)double a,double bpoint & pp.x3-9class box int len1,len2,len3;public: box(int l1,int l2,int l3)len1 = l1;len2 = l2; len3 = l3; long volumn()return len

6、1*len2*len3;3-10class Test int m1,m2; public: void Init(int a,int b)m1 = a;m2 = b; void Pring()coutm1 m2endl;3-11略3-12第四章4-6（1）D （2）D （3）D （4）D （5）B（6）D4-7（1）static int count = 0;这样初始化静态成员值是不对的将其改为static int count;在类外，main函数前加int Sample:count = 0;（2）#include /#include using namespace std;class Ctest

7、private: int x; const int y1;public: const int y2; Ctest(int i1,int i2):y1(i1),y2(i2) y1 =10;/y1 为常量不能赋值 x = y1; int readme() const;int Ctest:readme ()const int i; i = x; x+; /常函数内不能改变成员值 return x; int main() Ctest c(2,8); int i = c.y2; c.y2 = i;/y2为常量,不能改值 i = c.y1;/y1私有,类外不能访问 return 0;将出错语句全部注释4-

8、8(1)题中印刷错误，将class C构造函数改为：C()coutconstructor C:;运行结果为：constructor Aconstructor Bconstructor C(2)40(3)3434-9略4-10 #include #include class Student int number; char name20;public: Student(int i=0,char *s=0) /构造学生对象 number=i; strcpy(name,s); void Print() /输出结果 coutNumber:numberendl; coutName:namest2.num

9、ber; /返回成员number的比较结果int main() Student st5=Student(65,Li),Student(78,Zhang),Student(80,wang),Student(92,zhao),Student(50,zhen); int max = 0; int min = 0; for(int i=1;i5;i+) if(!greaterthan(stmax,sti) max = i; if(!greaterthan(sti,stmin) min = i; cout最大成绩:endl; stmax.Print (); cout最小成绩:endl; stmin.Pr

10、int (); return 0;4-11#include #include using namespace std;class Book char *name; char*author; int sale;public: Book() name = 0; author = 0; sale = -1; Book(char* a ,char* b,int c) name = new charstrlen(a)+1; strcpy(name,a); author = new charstrlen(b)+1; strcpy(author,b); sale = c; void print() cout

11、autor authorendl; coutname nameendl; coutprice saleendl; Book() if(!name ) delete name; if(!author)delete author; ;int main() Book b1(c+,li ai hua,12); Book b2;return 0; 第五章5-8 改错题答案不唯一(1) class DC int x; public: DC()x =100; ;(2)编译无错,但逻辑错误,可改为: class BC protected: int x; public: BC(int i=0)x = i;cla

12、ss DC:private BC public: DC(int i):BC(i);(3)将DC构造函数改为: DC(int i):BC(i)y = 0;5-9(1) base class(2) (10,5) (3,9-18,33) (13,19) (13,19-18,33) (13,19) 5-10#include using namespace std;class Shape int x,y;public: Shape(int ix,int iy)x = ix; y = iy; virtual void show()coutpos: x yendl;class Circle :public

13、Shape int radius;public: Circle(int ix,int iy,int r):Shape(ix,iy),radius(r) void show() Shape:show (); coutcircle: radiusendl;class Rect :public Shape int width,higth;public: Rect(int ix,int iy,int iw,int ih):Shape(ix,iy),width(iw),higth(ih) void show() Shape:show (); coutwidth and higth: width higt

14、hendl;int main() Shape s1(1,1); Rect r1(2,2,8,8); Circle c1(3,3,9); r1.show (); c1.show(); return 0; 第六章6-4 d=3 D:fun();6-5 C:print(),cinfo=2 C:print(),cinfo=2 D:print(),dinfo=4B类不能定义对象，否则编译通不过，因为B未定义基类A中的虚函数print(),它也是个虚基类。6-6#include using namespace std;class Mammalpublic: virtual void Speak() cou

15、tin Mammalendl;class Dog:public Mammalpublic: void Speak() coutdog barkSpeak (); return 0;运行结果: dog bark6-7#include using namespace std;class BaseClasspublic: virtual BaseClass() coutdestruct Baseendl;class Derived:public BaseClasspublic: Derived() coutdestruct derivedendl; ;int main() BaseClass *pb

16、ase; pbase = new Derived; delete pbase; 结果将不能正常执行子类析构6-8 以圆形和正方形为例#include using namespace std;class Shapepublic: virtual float area() = 0;class Circle :public Shape int radius;public: Circle(int r):radius(r) float area() return 3.14*radius*radius;class Square :public Shape int width;public: Square(

17、int w):width(w) float area() return width*width;int main() float areaSum= 0; Shape * pS3; pS1 = new Circle(1); pS2 = new Square(2); areaSum += pS1-area (); areaSum += pS2-area (); coutareaSumendl; return 0; 6-9#include using namespace std;class Studentpublic: virtual void show() = 0;class Junior :pu

18、blic Studentpublic: void show()coutthis would be info for junior studentsendl;class Senior :public Studentpublic: void show()coutthis would be info for Senior studentsshow ();pstu = new Senior;pstu-show ();return 0;第七章7-1#include #include using namespace std;class vector int x,y;public: vector(int i

19、x=0,int iy=0)x =ix;y = iy; vector operator+(vector& v1) return vector(x+v1.x,y+v1.y); vector& operator+=(vector& v1) x +=v1.x; y +=v1.y; return *this; void show() cout(x,y)endl; ;int main() vector v1(1,2),v2(3,4),v3; v3 = v1+v2; v1+=v2; v3.show(); v1.show(); return 0;7-2 #include class Complex priva

20、te: double real,image;public: Complex(double x=0.0,double y=0.0) real =x; image =y; bool operator !=(const Complex &c);Complex operator -(const Complex &c); bool operator =(const Complex &c); Complex operator -(); Complex &operator +=(const Complex &c); void Print();void Complex:Print() coutreal + i

21、mageiendl; Complex Complex :operator -(const Complex &c) Complex temp(real-c.real,image-c.image);return temp;bool Complex :operator =(const Complex &c) return (real=c.real & image=c.image); bool Complex:operator !=(const Complex &c) return (real!=c.real | image!=c.image); Complex Complex :operator -

22、() return Complex(-real,-image); Complex &Complex :operator +=(const Complex &c) real+=c.real; image+=c.image;return *this; int main() Complex c1(2,7),c2(4,2),c3; c3=c1-c2; c3.Print(); if(c3=c1)coutc3 equals to c1endl; else coutc3 doesn?t equale to c1endl; c3=-c2; c3.Print(); c3+=c2; c3.Print(); if(

23、c3 != c1) coutc3!=c1endl; return 0;7-3#include using namespace std;bool rn(int y) bool flag = 0; if(y%400=0 | y%4 =0&y%100!=0) flag = 1; return flag; class Date private: int month, day, year; public: Date(int m, int d, int y); Date& operator+(int days); void showDate(); ;Date:Date(int y, int m, int d) if (m0 & m0 & d0 & y0;) int diff ; switch(month) case 1: case 3: case 5: case 7: case 8: case 10: case 12: diff = 31 -day;break; case 4: case 6: case 9: case 11: diff = 30 -day;break; case 2:if (rn(year)diff = 29 - day; else diff = 28 -day; break; if(idiff) i-= diff+1; day = 1; month+;