1 #include<iostream> 2 #include<ctime> 3 #include <stdio.h> 4 #include<cstring> 5 #include<cstdlib> 6 #include <map> 7 #include <string> 8 using namespace std; 9 class A10 {11 public:12     A(){13         cout << "A()" << endl;14     }15 16     ~A(){17         cout << "~A()" << endl;18     }19     virtual void func(int val = 1)20     {21         std::cout << "A->" << val << std::endl;22     }23 24     virtual void test()25     {26         func();27     }28 };29 30 class B:public A31 {32 public:33     B(){34         cout << "B()" << endl;35     }36 37     ~B(){38         cout << "~B()" << endl;39     }40     void func(int val = 0)41     {42         std::cout << "B->" << val << std::endl;43     }44 };45 46 #if 147 int main(){48     B*p = new B;49     p->test();50     delete p;51 }52 #endif