多态 子类函数重写

1 #include<iostream>
  2 #include<string>
  3 using namespace std;
  4 class boss{
  5 public:
  6 int fight(){
  7         int ret = 10;
  8                 cout << "boss::fight():ret=" << ret << endl;
  9                 return ret;
 10         }
 11 };
 12 class master{
 13 public:
 14         virtual int eight(){
 15                 int ret = 8;
 16                 cout << "master::eight():ret=" << ret << endl;
 17                 return ret;
 18         }
 19 };
 20 class newmaster:public master{
 21 public:
 22         int eight(){
 23                 int ret = master::eight()*2;  
 24                 cout << "newmaster:eight():" << ret << endl;
 25                 return ret;
 26         }
 27 };
 28 void pk(master*master,boss*boss){
 29         int k = master->eight();
30         int b = boss->fight();
 31         if(k < b){
 32                 cout << "boss big" << endl;
 33         }else{
 34                 cout << "master big" << endl;
 35         }
 36 }
 37 int main(){
 38         boss b;
 39         newmaster n;
 40         pk(&n,&b);
 41         return 0;
 42 }

打印结果：

master::eight():ret=8// 这行是第23的master::eight()产生的。
newmaster:eight():16
boss::fight():ret=10
master big

//多态时候会将父 类被重写的函数也执行