好头痛啊，俺是新手，求朋友们帮帮忙
下面是我写的程序，定义一个book类存储书籍信息，编译成功，但是在运行时却好像发生了错误，运行的最后没有像以前那样显示：“请按任意键继续”，而且发出‘嘭’的一声提示音，好像是发生了什么错误，然后关不掉窗口，只能是点窗口右上角的叉强行关掉它，不明白为什么啊，希望有朋友能帮帮忙
注：应该是switch那个地方错了，但我怎么改也是那样没变化


//book.h

#include<iostream>
using namespace std;

//定义book类

class book
{
    char*bookname;
    double price;
    int number;
public:
    book(char *a="nobook", double b=0, int c=0);
    ~book();
    void display();
    void borrow();
    void restore();
    void set(char *e, double f, int g);
};


//book.cpp,定义函数

#include<iostream>
#include"aa.h"
using namespace std;

book::book(char *a, double b, int c)
{bookname=new char[40];bookname=a;price=b;number=c;}

book::~book()
{delete []bookname;bookname=NULL;}

void book::display()
{
    cout<<"bookname:"<<bookname<<endl
        <<"price:"<<price<<endl
        <<"number"<<number<<endl;
}

void book::borrow()
{
    number--;
    cout<<"number:"<<number<<endl;
}

void book::restore()
{
    number++;
    cout<<"number:"<<number<<endl;
}

void book::set(char *e, double f, int g)
{bookname=e;price=f;number=g;}

//main.cpp

#include<iostream>
#include"aa.h"
using namespace std;
int main()
{
    int h;
    book A;
    A.display();
    A.borrow();
    cout<<"What are going ti do?"<<endl;
    cin>>h;
    switch(h)
    {
    case 0:
        {
            char* e=new char[50];double f;int g;
            cout<<"name:"<<endl;
            cin>>e;
            cout<<"price"<<endl;
            cin>>f;
            cout<<"number:"<<endl;
            cin>>g;
            A.set(e,f,g);
            
        }
    case 1:
        {break;}
    case 2:
        {break;}
    default:
        {cout<<"error"<<endl;return -1;}
    }
}

//book.h

#include<iostream>
using namespace std;

//定义book类

class book
{
    char *bookname;
    double price;
    int number;
    public:
     book(char *a, double b, int c);  //你的构造函数的参数怎么可以赋值?
    ~book();
    void display();
    void borrow();
    void restore();
    void set(char *e, double f, int g);
};


//book.cpp,定义函数

#include<iostream>
#include"book.h"
using namespace std;

book::book(char *a, double b, int c)
{  bookname=new char[40];  bookname=a;  price=b; number=c; }

book::~book()
{ bookname=""; } //delete只能删除用new申请的内存,你确定所有的bookname都是new申请的?

void book::display()
{
    cout<<"bookname:"<<bookname<<endl
        <<"price:"<<price<<endl
        <<"number"<<number<<endl;
}

void book::borrow()
{
    number--;
    cout<<"number:"<<number<<endl;
}

void book::restore()
{
    number++;
    cout<<"number:"<<number<<endl;
}

void book::set(char *e, double f, int g)
{ bookname=e; price=f; number=g; }

//main.cpp

#include<iostream>
#include"book.cpp"
using namespace std;
int main()
{
    int h;
    book A;
    A.display();
    A.borrow();
    cout<<"What are going to do?"<<endl;
    cin>>h;
    switch(h)
    {
    case 0:
        {
            char *e=new char[50]; double f; int g;
            cout<<"name:";
            cin>>e;
            cout<<"price:";
            cin>>f;
            cout<<"number:";
            cin>>g;
            A.set(e,f,g);
          }  break;
    case 1:
           break;
    case 2:
           break;
    default:
        {  cout<<"error"<<endl;  return -1;  break;  }
    }
    return 0;
} //还有你的文件之间的相互包含关系要注意，哪一个前哪一个在后要分清！

构造函数那好象有点问题。应该加个  book（）{}

void book::set(char *e, double f, int g)
{bookname=new char[strlen(a)+1];strcpy(bookname,a);price=f;number=g;}
book::book(char *a, double b, int c)
{bookname=new char[40];strcpy(bookname,a);price=b;number=c;}

#include<iostream.h>
#include<string>
class book
{
    char*bookname;
    double price;
    int number;
public:
    book(char *a="nobook", double b=0, int c=0);
    ~book();
    void display();
    void borrow();
    void restore();
    void set(char *e, double f, int g);
};
book::book(char *a, double b, int c)
{bookname=new char[40];strcpy(bookname,a);price=b;number=c;}

book::~book()
{delete []bookname;bookname=NULL;}

void book::display()
{
    cout<<"bookname:"<<bookname<<endl
        <<"price:"<<price<<endl
        <<"number"<<number<<endl;
}

void book::borrow()
{
    number--;
    cout<<"number:"<<number<<endl;
}

void book::restore()
{
    number++;
    cout<<"number:"<<number<<endl;
}

void book::set(char *e, double f, int g)
{strcpy(bookname,e);price=f;number=g;}
int main()
{
    int h;
    book A;
    A.display();
    A.borrow();
    cout<<"What are going ti do?"<<endl;
    cin>>h;
    switch(h)
    {
    case 0:
        {
            char* e=new char[50];double f;int g;
            cout<<"name:"<<endl;
            cin>>e;
            cout<<"price"<<endl;
            cin>>f;
            cout<<"number:"<<endl;
            cin>>g;
            A.set(e,f,g);
            
        }break;
    case 1:
        break;
    case 2:
        break;
    default:
        {cout<<"error"<<endl;return -1;}break;
    }
    return 0;
}

谢谢啊，原来是被我delete内存空间，问题解决了，太谢谢了
不过不是可以对构造函数参数设置默认值吗？
还有求教一下：文件之间的相互包含关系要注意，哪一个前哪一个在后要分清！是什么意思啊，我是新手，很多都不太懂，求教求教
 

对构造函数初始化不是有两种方法啊，一是在函数体内，还有在初始化表中被初始化。
第一种：
book::book(char * a,double b,int c)
:"nobook"(a),b(0),c(0)
{}
第二种：
book::book(char * a,double b,int c)
｛
a="nobook";
b=0;
c=0;
｝