#include<iostream.h>
#include<stdlib.h>
class Stock
{
      char stockcode[10];
      int quan;
      double price;
public:
       Stock(char cd[],int q=1000 ,double p=8.98)
       {            
              strcpy(stockcode,cd);
              quan=q;
              price=p;   
       }
       void print(void);        
};
void Stock::print(void)
{
     cout<<this->stockcode<<" ";
     cout<<this->quan<<" ";
     cout<<this->price<<endl;
}            
int main()
{   
    Stock A="a",B("a",500,9.0);
    A.print();
    B.print();
    system("pause");
}
这个程序在声明构造函数时必须给出定义吗？
为什么在类外定义构造函数时会出错？

没又说要在声明构造函数时给出定义，你把你错误的代码贴贴~

#include<iostream.h>
#include<stdlib.h>
class Stock
{
      char stockcode[10];
      int quan;
      double price;
public:
       Stock(char cd[],int q=1000 ,double p=8.98);
             void print(void);        
};
Stock::Stock(char cd[],int q=1000 ,double p=8.98)
 {            
              strcpy(stockcode,cd);
              quan=q;
              price=p;   
      }

void Stock::print(void)
{
     cout<<this->stockcode<<" ";
     cout<<this->quan<<" ";
     cout<<this->price<<endl;
}            
int main()
{   
    Stock A="a",B("a",500,9.0);
    A.print();
    B.print();
    system("pause");
}
只是把构造函数放在类外定义就出错了

#include<iostream.h>
#include<stdlib.h>
#include<string.h>
class Stock
{
      char stockcode[10];
      int quan;
      double price;
public:
       Stock(char cd[],int q=1000 ,double p=8.98);
             void print(void);        
};
Stock::Stock(char cd[],int q=1000 ,double p=8.98)   //默认参数只在声明时指出，这里时定义就不要指出了
                                                                                        改成(char cd[], int q, double p)
{            
              strcpy(stockcode,cd);
              quan=q;
              price=p;   
      }

void Stock::print(void)
{
     cout<<this->stockcode<<" ";
     cout<<this->quan<<" ";
     cout<<this->price<<endl;
}            
int main()
{   
    Stock A="a",B("a",500,9.0);
    A.print();
    B.print();
    system("pause");
return 0;
}

我是初学者，请问strcpy(stockcode,cd);这是什么意思啊？

就是把cd的值赋给stockcode
strcpy是字符串拷贝函数






问题解决了
谢谢四楼了

[[italic] 本帖最后由 o0花生0o 于 2007-12-6 18:29 编辑 [/italic]]

明白了，谢谢你~

还有一个问题就是要有一个处理字符串函数的头文件.

没有处理字符串函数的头文件编译也没有出错

我想问一下，strcpy(stockcode,cd);是如何实现值复制的呢，说具体一些好吗