Question

VC++ 6.0下：C++程序出错，求高人指点“哪里出错”了。。。谢谢！

代码如下：
#include <iostream.h>
#include <string.h>
class Student
{
public:
Student() {}
Student(int n,char* na,char s) {num=n;strcpy(name,na);sex=s;}
void in()
{ num=1001;
name="lee";
sex='M'; }
private:
int num;
char* name;
char sex;
};
class Teacher
{
public:
Teacher() {}
Teacher(int n,char* na,char s) {num=n;strcpy(name,na);sex=s;}
Teacher(Student& s) {num=s.num;strcpy(name,s.name);sex=s.sex;}
void out()
{ cout<<num<<" "<<name<<" "<<sex<<endl; }
private:
int num;
char* name;
char sex;
};

int main()
{ Student s;
Teacher(& s);
s.in();
s.out();
return 0;
}
错误提示：
--------------------Configuration: 4 - Win32 Debug--------------------
Compiling...
4.cpp
E:\C++\4.cpp(24) : error C2248: 'num' : cannot access private member declared in class 'Student'
E:\C++\4.cpp(15) : see declaration of 'num'
E:\C++\4.cpp(24) : error C2248: 'name' : cannot access private member declared in class 'Student'
E:\C++\4.cpp(16) : see declaration of 'name'
E:\C++\4.cpp(24) : error C2248: 'sex' : cannot access private member declared in class 'Student'
E:\C++\4.cpp(17) : see declaration of 'sex'
E:\C++\4.cpp(35) : error C2040: 's' : 'class Teacher &' differs in levels of indirection from 'class Student'
E:\C++\4.cpp(35) : error C2530: 's' : references must be initialized
执行 cl.exe 时出错.

4.obj - 1 error(s), 0 warning(s)

Answer 1

Teacher(Student& s) {num=s.num;strcpy(name,s.name);sex=s.sex;}
这里，Student的num是private的，所以外面不可以访问。
Teacher(& s); 调用的时候写成Teacher(s);就行了。但是这里还有问题就是没有给这个变量命名。
所以写成Teacher t(s);
然后
s.in();
t.out();

追问

谢啦，但改后还有错啊：
error C2228: left of '.name' must have class/struct/union type
error C2228: left of '.sex' must have class/struct/union type
error C2248: 'num' : cannot access private member declared in class 'Student'
see declaration of 'num'
error C2248: 'name' : cannot access private member declared in class 'Student'
（等等。。）
执行 cl.exe 时出错. 1 error(s), 0 warning(s)

追答

#include
#include
using namespace std;

class Student
{
public:
Student() {}
Student(int n,char* na,char s) {num=n;strcpy(name,na);sex=s;}
void in()
{ num=1001;
name="lee";
sex='M'; }
int num;
char* name;
char sex;
private:

};
class Teacher
{
public:
Teacher() {}
Teacher(int n,char* na,char s) {num=n;strcpy(name,na);sex=s;}
Teacher(Student& s) {
num=s.num;
name=new char[strlen(s.name)+1];
strcpy(name,s.name);
sex=s.sex;}
void out()
{ cout<<num<<" "<<name<<" "<<sex<<endl; }
private:
int num;
char* name;
char sex;
};

int main()
{ Student s;
s.in(); //我不确定你原来的用意，在s.in()调用之前s中的数据都没初始化。
Teacher t(s);
t.out();
return 0;
}

Answer 2

把num改为public

Answer 3

把num改为public