例12.2 基類與派生類中有同名函數(shù)。
在下面的程序中Student是基類，Graduate是派生類，它們都有display這個(gè)同名的函數(shù)。
#include <iostream>
#include <string>
using namespace std;
//聲明基類Student
class Student
{public:
   Student(int, string,float);//聲明構(gòu)造函數(shù)
   void display( );                                             //聲明輸出函數(shù)
  protected:                                      //受保護(hù)成員，派生類可以訪問 
   int num;
   string name;
   float score;
 };
//Student類成員函數(shù)的實(shí)現(xiàn)
Student::Student(int n, string nam,float s)                     //定義構(gòu)造函數(shù)
 {num=n;name=nam;score=s;}

void Student::display( )                                        //定義輸出函數(shù)
{cout<<″num:″<<num<<″\\nname:″<<name<<″\\nscore:″<<score<<″\\n\\n″;}

//聲明公用派生類Graduate
class Graduate:public Student
{public:
   Graduate(int, string, float, float);                          //聲明構(gòu)造函數(shù)
   void display( );                                             //聲明輸出函數(shù)
private:
  float pay;
};
// Graduate類成員函數(shù)的實(shí)現(xiàn)
void Graduate::display( )                                       //定義輸出函數(shù)
 {cout<<″num:″<<num<<″\\nname:″<<name<<″\\nscore:″<<score<<″\\npay=″<<pay<<endl;}

Graduate::Graduate(int n, string nam,float s,float p):Student(n,nam,s),pay(p){ }

//主函數(shù)
int main()
 {Student stud1(1001,″Li″,87.5);                   //定義Student類對(duì)象stud1
  Graduate grad1(2001,″Wang″,98.5,563.5);          //定義Graduate類對(duì)象grad1
  Student *pt=&stud1;                              //定義指向基類對(duì)象的指針變量pt
  pt->display( );
  pt=&grad1;
  pt->display( );
  return 0;
 }