C++期中测验试卷2

期中测验试卷2、请划出下列程序中的错误点，并说明出错原因：(本大题共10题，每小题3分，共30分)(说明：指编译、或者运行时出的错误。

)1、#include<iostream.h>#include<string.h>class vehicle{ int wheels=4; //error: 不可以这样初始化char color[8]="green"; //error: 不可以这样初始化 public:vehicle(int w,char*c){ wheels=w; strcpy(color,c); }void show(){ cout<<"color: "<<color<<" wheels: "<<wheels<<endl; } };void main(){ vehicle v1(6,"grey"),v2(4,"green");v1.show(); v2.show();}2、#include<iostream.h>class A{ int const x;public:A(int y=0) //error：const的数据成员只能通过初始化列表来初始化{ x=y; }};void main(){ A aa(555); }3、#include<iostream.h>class A{ int a,b;public:virtual A(int aa=0,int bb=0) //error: 构造函数不能定义为虚函数 { a=aa; b=bb;cout<<"A1 class!"<<endl;}virtual void show(){ cout<<"A: a="<<a<<" b="<<b<<endl; }};class B:public A{ public:B(int aa=0,int bb=0):A(aa,bb){ cout<<"A2 class!"<<endl; }void show(){ cout<<"B: "<<endl; }};void main(){ B b; b.show(); }4、#include<iostream.h>#include<string.h>class Person{ protected:char name[10],sex;int age;public:Person(char *n="",char s=' ',int a):sex(s),age(a)//error：{ strcpy(name,n); } //违反缺省值的次序规定void show(){ cout<<name<<””<<sex<<””<<age<<endl; } };void main(){ Person s1("Li si",’m’,20),s2("Zhang san",’w’,19);s1.show(); s2.show();}5、#include "iostream.h"void main(){ const float pi,*fp; //error: const常量pi必须初始化float r=8.9;fp=&r;pi=3.14; //error: pi是const常量，不能做左值cout<<" The circle erea is: "<<pi*r*r<<endl;}6、#include<iostream.h>class Pro{ private: int *p;public:Pro(int &i){ p=new int(i); cout<<"Constractor..."<<endl; } ~ Pro(){ delete p; cout<<"delete p..."<<endl; }void display(){ cout<<*p<<endl; }};void main(){ Pro p1(2003); //error: a(int &i)；不能引用到一个常量上p1.display();}7、#include<iostream.h>class A{ protected: int *num;public:A(){ num=new int[10];for(int i=0;i<10;++i){ cout<<"input num["<<i<<"] : "; cin>>num[i]; cout<<endl; } }void show(){ for(int i=0;i<10;++i) cout<<num[i]<<endl; }};class B: public A{ protected: int x;public:B(int xx){ x=xx; }};void main(){ A a,*pa=&a;pa->show();B b1(12),*pb;pb=&a; //error: 派生类的指针不能指向基类的对象pb->show();pa=&b1;pa->show();}8、#include<iostream.h>template<class Type1,class Type2,class Type3>Type3 function(Type1 x1,Type2 x2){ Type3 temp=x1+x2;cout<<x1<<endl;cout<<x2<<endl;return(temp*x1+temp*x2);}void main(){ int x1=100;float x2=1903.5;double y=function(x1,x2); //error: 不能推断出模板函数中的Type3cout<<y<<endl; //模板函数的返回类型参数必须是形参类型之一}9、#include<iostream.h>class B0{ protected: int B0x;public:B0(int xx){ B0x=xx; }void display(){ cout<<"B0::display() B0x="<<B0x<<endl; }};class B1: public B0{ public:int B1x;B1(int x1,int x2):B0(x1),B1x(x2){ }void display(){ cout<<"B1::display() B1x="<<B1x<<endl; }};void main(){ B0 *p;B1 b1(99,77); p=&b1;p->display();cout<<p->B1x<<endl; //error: 父类指针指向子类，通过指针只能访问父类的成员}10、#include<iostream.h>class Date{ public:int year,month,day;Date(int y=1900,int m=1,int d=1){ year=y; month=m; day=d; }void input(){ cin>>year; cin>>month; cin>>day; }};class Student{ int num;char *name;Date birthdate;public:Student(int n,char *na,int y=1900,int m=1,int d=1):birthdate(y,m,d) { num=n; name=na; }void display(){ cout<<num<<" "<<name<<"’birthdate ：";cout<<"Date: "<<month<<"-"<<day<<"-"<<year<<endl;//error: 应该birthdat.month, birthdat.day, birthdat.year }};void main(){ Student s1(1,"Smith"),s2(2,"Deitel",1950,12,3);s1.display(); s2.display();}。