第三周作业（一）

#include <iostream>
using namespace std;
class Student
{
public:
void set_data(int n, char *p,char s);
void display( );
private:
int num;
char name[20];
char sex;
};

void Student::set_data(int n, char *p,char s)
{
num=n;
strcpy(name,p);
sex=s;
}
void Student::display( )
{
cout<<"num: "<<num<<endl;
cout<<"name: " <<name<<endl;
cout<<"sex: " <<sex<<endl;
}
int main()
{
Student stud1,stud2;
stud1.set_data(1,"He",'f');
stud2.set_data(2,"She",'m');
stud1.display();
stud2.display();
return 0;
}

//找错误1：违反封装原则，直接给私有成员赋值，访问私有对象
/*int main()
{
Student stud1,stud2;
num=1;
name=she;
sex=m;
stud1.set_data(1,"He",'f');
stud2.set_data(2,"She",'m');
stud1.display();
stud2.display();
return 0;
}
--------------------Configuration: 1 - Win32 Debug--------------------
Compiling...
1.cpp
C:\Documents and Settings\user\桌面\程序设计\1.cpp(29) : error C2065: 'num' : undeclared identifier
C:\Documents and Settings\user\桌面\程序设计\1.cpp(30) : error C2065: 'name' : undeclared identifier
C:\Documents and Settings\user\桌面\程序设计\1.cpp(30) : error C2065: 'she' : undeclared identifier
C:\Documents and Settings\user\桌面\程序设计\1.cpp(31) : error C2065: 'sex' : undeclared identifier
C:\Documents and Settings\user\桌面\程序设计\1.cpp(31) : error C2065: 'm' : undeclared identifier
Error executing cl.exe.

1.obj - 5 error(s), 0 warning(s)*/

//在实现对类成员函数时不指定作用域
/*void set_data(int n, char *p,char s)
{
num=n;
strcpy(name,p);
sex=s;
}
void Student::display( )
{
cout<<"num: "<<num<<endl;
cout<<"name: " <<name<<endl;
cout<<"sex: " <<sex<<endl;
}
--------------------Configuration: 1 - Win32 Debug--------------------
Compiling...
1.cpp
C:\Documents and Settings\user\桌面\程序设计\1.cpp(16) : error C2065: 'num' : undeclared identifier
C:\Documents and Settings\user\桌面\程序设计\1.cpp(17) : error C2065: 'name' : undeclared identifier
C:\Documents and Settings\user\桌面\程序设计\1.cpp(18) : error C2065: 'sex' : undeclared identifier
Error executing cl.exe.

1.obj - 3 error(s), 0 warning(s)*/

//调用stud1.set_data()函数时，实参出现不当类型：
/*int main()
{
Student stud1,stud2;

stud1.set_data(1,"He",'f');
stud2.set_data(x,"She",'m');
stud1.display();
stud2.display();
return 0;
}
--------------------Configuration: 1 - Win32 Debug--------------------
Compiling...
1.cpp
C:\Documents and Settings\user\桌面\程序设计\1.cpp(31) : error C2065: 'x' : undeclared identifier
Error executing cl.exe.

1.obj - 1 error(s), 0 warning(s)*/