C++期末复习(程序分析)

1、C+期末复习（程序分析题） 一、程序改错题 1、指出下面程序段中的错误，并说明出错原因。 class Aint a,b; public ： A(int aa,int bb) a=aa;b=bb; ; void main()A x(2,3),y(4); 答：Ax(2,3),y(4); 语句出错，因为没有单参数的构造函数 ( 或者 y(4) 少写了一个参数 ) 。2、指出并改正下面利用类模板的对象定义中的错误。 template <class T> class Tany T x,y; public: Tany(T a,T b)x=a,y=b; T sum( )return x+y; ;

2、 void main()Tany (int) obj(10,100); 答：Tany(int) obj(10,100); 出错，应为 Tany<int> obj(10,100); 语句。 3、 指出下面程序段中的错误，并说明出错原因。 class oneprivate: int a; public: void func(two&); ; class twoprivate: int b; friend void one:func(two&); ; void one:func(two& r) a=r.b; 答：void func(two&); 出错， t

3、wo 尚未声明 (应在 class one 前加声明语句 class two ； ) 。 4、指出下面程序段中的错误，并说明出错原因。 include <iostream.h> class Apublic: void fun( )cout<< a.fun <<endl; ; class B public:void fun( )cout<< b.fun <<endl; void gun( )cout<< b.gun <<endl; ; class C:public A,public Bprivate:int b;

4、 public:void gun( ) cout<< c.gun <<endl; void hun( ) fun( ); ; 答：void hun()fun(); 出错， C ： fun() 有二义性。5、指出下面程序段中的错误，并说明出错原因。 class Location int X,Y=20; protected: int zeroX,zeroY; int SetZero(int ZeroX,int ZeroY); private: int length,height; public: float radius; void init(int initX,int i

5、nitY); int GetX( ); int GetY( ); ;答：int X,Y=20; 出错，不能采用这种方式初始化。6、下面的程序类 B 的定义中有一处错误，请用下横线标出错误所在行并说明错误原因。 # include<iostream.h> # include<string.h> class Apublic:A(const char *nm)strcpy(name,nm); private:char name80; ; class B:public Apublic:B(const char *nm):A(nm) void PrintName( )const;

6、 ; void B:PrintName( )const cout<< " name: " <<name<<endl; /错误，name为私有成员 void main( )B b1( " wang li " ); b1.PrintName( ); 7、用下横线标出下面程序 main 函数中的错误所在行，并说明错误原因。 # include<iostream.h> class Locationprivate: int X,Y; public: void init(int initX,int initY); in

7、t sumXY( ); ; void Location:init(int initX,int initY) X=initX;Y=initY; int Location:sumXY( ) return X+Y; void main( ) Location A1; int x,y; A1.init(5,3); x=A1.X;y=A1.Y; cout<<x+y<< " " <<A1.sumXY( )<<endl; /错误 8、下面的程序有一处错误，请用下横线标出错误所在行并改正错误。# include<iostream.h&g

8、t; class Test public: static int x; ; int x=20; / 对类的静态成员初始化错误 void main ( ) cout<<Test:x; 9、指出下面的程序中的两处错误，并改正class Exampublic:Exam(int y=10) data=y; int getdata() const return +data; /错误常成员函数不能修改对象/修改方法：删除关键字conststatic int getcount()cout<<data;/ 错误静态成员函数不能直接访问非静态成员/修改方法：删除cout这一行return

9、 +count ; private:int data;static int count; ;10、指出下面的程序中的错误，并改正char *string;string=new charfree(string);/用new动态分配的内存不能用free函数来释放/修改方法：用delete运算符来释放11、指出下面的程序中的错误#include <iostream.h>#include <string.h>class Personpublic: Person(char* pN) cout <<"Constructing " <<pN

10、 <<endl; pName=new charstrlen(pN)+1; if(pName!=0) strcpy(pName,pN); Person() cout <<"Destructing " <<pName <<endl; pName0='0' delete pName; protected: char* pName;void main() Person p1("Randy"); Person p2=p1; /即Person p2(p1);/对同一个空间的两次释放，修改方法：增加一个复

11、制构造函数Person:Person(Person& p) pName=new charstrlen(p.pName)+1; strcpy(pName,p.pName);五、写出下面程序的执行结果 1、# include <iostream.h> class A int * a; public: A (int x) a = new int(x); cout<<"*a = "<<*a<<endl; delete a; ; void main() A x(3), *p; p = new A (5); delete p; 输

12、出为：*a=3*a=52、# include <iostream.h> template <class T, class Q> void f (T &x, Q &y) if (sizeof (T) > sizeof (Q) x = (T)y; else y = (Q)x; void main() double d; int i; d = 9999; i = 88; f(d,i); cout << "d=" << d << " i= " << i <<

13、 endl; d = 88; i = 9999; f(i,d); cout << "d=" << d << " i= " << i << endl; 输出为：d=88 i=88d=9999,i=99993、# include <iostream.h> class base public: virtual int func () return 0; ; class derived: public base public: int func() return 100; ; void ma

14、in() derived d; base & b = d; cout << b.func() << endl; cout << b.base:func() << endl; 输出为：10004、# include <iostream.h> class Test private: static int val; int a; public: static int func(); static void sfunc(Test &r); ; int Test:val = 20; int Test:func() val +=

15、val; return val; void Test:sfunc(Test &r) r.a = 25; cout << "Result3 = " << r.a<<endl; void main() cout << "Result1 = " << Test:func() << endl; Test a; cout << "Result2 = " << a.func()<<endl; Test:sfunc(a); 输出为：R

16、esult1 =40Result2=80Result3=255、#include<iostream.h> template<class T> class Tclassprivate:T x,y; public: Tclass(T a,T b):x(a)y=b; Tclass(T a)y=(T)0,x=a; void pr( )char c; c=(y>=(T)0 ? '+':'-'); cout<< x << c <<(y>(T)0? y:-y)<< "i"&

17、lt;<endl; ; void main( ) Tclass <double> a(10.5,-5.8); a.pr( ); Tclass <int> b(10); b.pr( ); 输出为：10.5-4.8i10+0i6、#include<iostream.h> class testpublic:test()cout <<"调用构造函数"<<endl; ;void f(int i)static test x;cout <<i<<endl; void main()f(10);f(20

18、);输出为：调用构造函数10207、include <iostream.h> void main( ) int *a; int *&p=a; int b=10; p=&b; cout<<*a; 输出为：108、 include <iostream.h> template<class T> Tf(T*a,T*b,int n) Ts=(T)0; for(int i=0;i<n;i+) s+=a i *b i ； return s; void main() double c 5 =1.1,2.2,3.3,4.4,5.5,d 5 =

19、10.0,100.0,1000.0; cout<<f(c,d,5)<<endl; 输出为：3531 9、#include <iomanip.h> void main() for(int i=0;i<4;i+) cout<<endl<<setfill(' ')<<setw(4-i)<< '0' <<setfill('#')<<setw(i+i)<<(i>0?'0':' ' ); 输出为：

20、 0 0#0 0#0 0#0 10、运行下面的程序，写出当输入 25 ， 60 时的输出结果。 #include <iostream.h> class goods private: static int totalWeight; int weight; public: goods(int w) weight=w; totalWeight+=w; goods(goods& gd) weight=gd.weight; totalWeight+=weight; goods() totalWeight-=weight; int getwg() return weight; stat

21、ic int getTotal() return totalWeight; ; int goods:totalWeight=0; void main() int w; cout<< "The initial weight of goods:"<<goods:getTotal()<<endl; cin>>w; / 输入 25 goods g1(w); cin>>w; / 输入 60 goods g2(w); cout<< "The total weight of goods:" <

22、;<goods:getTotal()<<endl; 输出为： The initial weight of goods:0 The total weight of goods:8511、# include<iostream.h> class A public: virtual void print( )cout<< " This is class A printing. " <<endl; ; class B:public A public: void print( ) ; class C:public B public:

23、 void print( )cout<< " This is class C printing. " <<endl; ; void show(A&a) a.print( ); void main( ) A a;B b;C c; show(a);show(b);show(c); 输出为：This is class A printing.This is class C printing.12、# include<iostream.h> class Apublic: A( )a=0; A(int i)a=i; void Print( )

24、cout<<a<< " , " ; int Geta( )return a; private:int a; ; class B:public Apublic:B( )b=0; B(int i,int j,int k); void Print( ); private:int b; A aa; ; B:B(int i,int j,int k):A(i),aa(j)b=k; void B:Print( ) A:Print( ); cout<<b<< " , " <<aa.Geta( )<<

25、endl; void main( ) B bb2; bb0=B(1,2,5); bb1=B(3,4,7); for(int i=0;i<2;i+) bbi.Print( ); 输出为：1, 5, 23, 7, 413、#include<iostream.h> class Testprivate: static int val; int a; public: static int func( ); void sfunc(Test &r); ; int Test:val=200; int Test:func( ) return val+; void Test:sfunc(

26、Test &r) r.a=125; cout<< "Result3=" <<r.a<<endl; void main( ) cout<< "Result1=" <<Test:func( )<<endl; Test a; cout<< "Result2=" <<a.func( )<<endl; a.sfunc(a); 输出为：Result1 =200Result2=201Result3=12514、# include<

27、;iostream.h> class Locationint X,Y; public: void init(int=0,int=0); void valueX(int val)X=val; int valueX( )return X; void valueY(int val)Y=val; int valueY( )return Y; ; void Location:init(int initX,int initY) X=initX; Y=initY; void main( ) Location A,B; A.init( ); cout<<A.valueX( )<<

28、" "<<A.valueY( )<<endl; A.valueX(5); cout<<A.valueX( )<<" "<<A.valueY( )<<endl; B.init(6,2); B.valueY(4); cout<<B.valueX( )<<" "<<B.valueY( )<<endl; 输出为：0 05 06 415、#include <iostream.h> class A public: A

29、( ) virtual void func( )cout<<"Destructor A" <<endl; A( ) func(); ; class B:public A public: B( ) void func()cout<<"Destructor B" <<endl; B( ) func(); ; void main( ) B b; A&a=b; 输出为：Destructor B Destructor A16、 include <iostream.h> class My Class

30、 public: int number; void set(int i); ; int number=3; void MyClass:set (int i) number=i; void main() MyClass my1; int number=10; my1.set(5); cout<<my1.number<<end1; my1.set(number); cout<<my1.number<<endl; my1.set(:number); cout<<my1.number; 输出为：5 10 3 17、#include<io

31、stream.h> class AAA int A,B; public: AAA(int i,int j) A=i,B=j; cout<<"Cn" AAA()cout<<"Dn" void print( ) cout<<A<<","<<B<<"n" ;void main() AAA *a1,*a2; a1=new AAA(1,2); a2=new AAA(5,6); a1->print(); a2->print(); dele

32、te a1; delete a2; 输出为：CC1,25,6 DD 18、#include <iostream.h> class b1 public: b1(int x) cout<<x<<"->An" b1() cout<<"Bn" ; class b2 public: b2(int x) cout<<x<<"->Cn" b2() cout<<"Dn" ; class AAA:public b2,public b1 p

33、ublic: AAA(int x,int y):b1(y),b2(x) cout<<"En" AAA()cout<<"Fn" ;void main() AAA obj(5,7); 输出为：5->C7->AEFBD19、#include<iostream.h> class FATHER public: virtual void answer( ) cout<<"I am fathern" ; class DAUGHTER:public FATHER public: virtua

34、l void answer( ) cout<<"I am daughtern"class SON:public FATHERpublic: void answer()cout<<"I am sonn" ;void main() FATHER father; DAUGHTER daughter; SON son; FATHER *who; who=&father; who->answer(); who=&daughter; who->answer(); who=&son; who->answ

35、er(); 输出为：I am fatherI am daughterI am son20、#include <iostream.h>class Basepublic: Base()cout<<"Generate Base"<<endl; Base()cout<<"Destroy Base"<<endl; ; class child:public Base public:child():Base()cout<<"Generate child"<<endl

36、; child()cout<<"Destroy child"<<endl; ; void main()child c2;输出为：Generate BaseGenerate childDestroy childDestroy Base21、#include <iostream.h>#include <string.h>class StudentIDpublic: StudentID(int id=0) value=id; cout <<"Assigning student id " <<

37、;value <<endl; StudentID() cout <<"Destructing id " <<value <<endl; protected: int value;class Studentpublic: Student(char* pName="noName",int ssID=0) cout <<"Constructing student " <<pName <<endl; strncpy(name,pName,sizeof(name

38、); namesizeof(name)-1='0' StudentID id(ssID); protected: char name20; StudentID id;void main() Student s("Randy",9818);输出为：Assigning student id 0Constructing student RandyAssigning student id 9818Destructing id9818Destructing id 022、#include <iostream.h>class MyClasspublic: M

39、yClass(); MyClass(int); MyClass(); void Display();protected: int number;MyClass:MyClass() cout <<"Constructing normally.n" MyClass:MyClass(int m): number(m) cout <<"Constructing with a number: " <<number <<endl;void MyClass:Display() cout <<"Dis

40、play a number: " <<number <<endl; MyClass:MyClass() cout <<"Destructing.n" void main() MyClass obj1; MyClass obj2(20); obj1.Display(); obj2.Display();输出为：Constructing normally.Constructing with a number: 20Display a number: 1/此处为不确定的数Display a number: 20Destructing.D

41、estructing.23、#include <iostream.h>#include <string.h>class Student protected: char name40;public: Student(char* pName="no name") cout <<"Constructing new student " <<pName <<endl; strncpy(name,pName,sizeof(name); namesizeof(name)-1='0' Stude

42、nt(Student& s) cout <<"Constructing copy of " << <<endl; strcpy(name,"copy of "); strcat(name,); Student() cout <<"Destructing " <<name <<endl; ;class Tutorprotected: Student student;public: Tutor(Student& s):student(s) cout <<"Constructing tutorn" ;void fn(Tutor tutor) cout <<"In function fn()n"void main() Student randy("Randy"); Tuto