c++高级程序设计语言实验十一拷贝构造函数

实验名称	拷贝构造函数
实验目的	理解何时会调用拷贝构造函数。 理解何时需要自定义拷贝构造函数。
实验任务	验证教材第十四章例子程序ch14_01（第307页 修正版第317页）、ch14_02（第308页 修正版第318页）、ch14_3（第310页 修正版第320页）、ch14_04（第311页 修正版第321页）。 结合习题,理解拷贝构造函数的使用。 14.2（第317页 修正版第327页） ex14_02 写出下面程序的运行结果，请用增加拷贝构造函数的方法避免存在的问题。 #include <iostream> using namespace std; class Vector {   public:      Vector(int s=100);      int& Elem(int ndx);      void Display();      void Set();      ~Vector();   protected:      int size;      int* buffer; }; Vector::Vector(int s) {   buffer=new int[size=s];   for(int i=0; i<size; i++)      buffer[i]=i*i; } int& Vector::Elem(int ndx) {   if(ndx<0||ndx>=size) {      cout <<"error in index" <<endl;      exit(1);   }   return buffer[ndx]; } void Vector::Display() {   for(int j=0; j<size; j++)      cout <<buffer[j] <<endl; } void Vector::Set() {   for(int j=0; j<size; j++)      buffer[j]=j+1; } Vector::~Vector() {   //cout << "~Vector begin." << endl;   delete[]buffer;   //cout << "~Vector end." << endl; } int main() {   Vector a(10);   Vector b(a);   a.Set();   b.Display();   return 0; }
实验内容 ch14_01 #include<iostream> #include<cstring> using namespace std; class Student {    char name[40];    int id;    public:       Student(char *pName= "no name",int ssId = 0)       {           strncpy(name,pName,40);           name[39]='\0';           id=ssId;           cout << "Constructing new student"<< pName<< endl;       }       Student(Student&s)       {           cout << "Constructing copy of"<< s.name<<endl;           strcpy(name,"copy of");           strcat(name,s.name);           id=s.id;       }       ~Student()       {           cout << "Sestructing "<< name << endl;       } }; void fn(Student s) {    cout << "In function fn() "<< endl; } int main() {    Student randy("Randy",1234);    cout << "Calling fn()"<< endl;    fn(randy);    cout << "Returned from fn()"<< endl;    return 0; } ch14_02 #include<iostream> #include<cstring> using namespace std; class Student {    char name[40];    int id;    public:       Student(char *pName= "no name")       {           cout << "Constructing new student"<< pName<< endl;           strncpy(name,pName,sizeof(name));           name[sizeof(name)-1]='\0';       }       Student(Student&s)       {           cout << "Constructing copy of"<< s.name<<endl;           strcpy(name,"copy of");           strcat(name,s.name);       }       ~Student()       {           cout << "Destructing "<< name << endl;       } }; class Tutor {    Student student;    public:       Tutor(Student&s):student(s)       {           cout << "Constructing tutor"<< endl;       } }; void fn(Tutor tutor) {    cout << "In function fn() "<< endl; } int main() {    Student randy("Randy");    Tutor tutor(randy);    cout << "Calling fn()"<< endl;    fn(tutor);    cout << "Returned from fn()"<< endl;    return 0; } ch14_03 #include<iostream> #include<cstring> using namespace std; class Person {    char * pName;    public:       Person(char * pN)       {           cout << "Constructing"<<pN<< endl;           pName= new char[strlen(pN)+1];           if(pName!=0)           strcpy(pName,pN);       }       ~Person()       {           cout <<"Destructing"<< pName<< endl;           pName[0]='\0';           delete pName;       } }; int main() {    Person p1("Randy");    Person p2= p1;    return 0; } ch14_04 #include<iostream> #include<cstring> using namespace std; class Person {    char * pName;    public:       Person(char * pN);       Person(Person &p);       ~Person(); };    Person::Person(char * pN)    {       cout << "Constructing"<<pN<< endl;       pName= new char[strlen(pN)+1];       if(pName!=0)       strcpy(pName,pN);    }    Person::Person(Person& p)    {       cout <<"Copying"<< p.pName<<"into its own block"<< endl;       pName = new char[strlen(p.pName)+1];       if(pName!=0)       strcpy(pName,p.pName);    }          Person::~Person()    {       cout <<"Destructing"<< pName<< endl;       pName[0]='\0';       delete pName;    } int main() {    Person p1("Randy");    Person p2= p1;    return 0; } ex14_02 #include <iostream> using namespace std; class Vector {    public:       Vector(int s=100);       Vector(Vector& v);       int& Elem(int ndx);       void Display();       void Set();       ~Vector();    protected:       int size;       int* buffer; }; //深拷贝 Vector::Vector(Vector& v) {    buffer= new int[size=v.size];    for(int i=0;i<v.size;i++)    {       buffer[i]=i*i;    } } Vector::Vector(int s) {    buffer=new int[size=s];    for(int i=0; i<size; i++)       buffer[i]=i*i; } int& Vector::Elem(int ndx) {    if(ndx<0||ndx>=size) {       cout <<"error in index" <<endl;       exit(1);    }    return buffer[ndx]; } void Vector::Display() {    for(int j=0; j<size; j++)       cout <<buffer[j] <<endl; } void Vector::Set() {    for(int j=0; j<size; j++)       buffer[j]=j+1; } Vector::~Vector() {    //cout << "~Vector begin." << endl;    delete[]buffer;    //cout << "~Vector end." << endl; } int main() {    Vector a(10);    Vector b(a);    a.Set();    b.Display();    return 0; }
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