例题

#include<iostream.h>
class student
{
private :
    int id;
     float chinese,math,english;
    public :
  student();
  student(int m_id,float m_chinese,float m_math,float m_english);
  void show();
};
 //无参数构造函数的定义，初始化各属性；
student::student()
{id=0;
chinese=english=math=0;
}
//有参数构造函数的定义,初始化各属性；
student::student(int m_id,float m_chinese,float m_math,float m_english)
{
 id=m_id;
 chinese=m_chinese;
 math=m_math;
 english=m_english;
}
void student::show()
{
 cout<<id<<endl;
    cout<<chinese<<endl;
    cout<<english<<endl;
}
int main()
{

 

 student s1(1001,100,98,87);
 s1.show();
 student s2(s1);
 s2.show();
 return 0;
}