1 #include <iostream> 
 2 #include<stdlib.h>
 3 using namespace std; 
 4 
 5 class A 
 6 { 
 7 public: 
 8     int _a; 
 9     A() 
10     { 
11         _a = 1; 
12     } 
13     void print() 
14     { 
15         printf("%d\n", _a); 
16     } 
17 }; 
18 
19 class B: public A 
20 { 
21 public: 
22     int _a; 
23     B() 
24     { 
25         _a = 2; 
26     } 
27 }; 
28 
29 int main() 
30 { 
31     B b; 
32     b.print(); 
33     printf("%d\n", b._a); 
34     return 0; 
35 }

 1 #include <iostream> 
 2 #include<stdlib.h>
 3 using namespace std; 
 4 
 5 class base 
 6 { 
 7 private: 
 8     int m_i; 
 9     int m_j; 
10 public: 
11     base(int i):m_j(i),m_i(m_j){} 
12     base():m_j(0),m_i(m_j){} 
13     int get_i(){return m_i;} 
14     int get_j(){return m_j;} 
15 }; 
16 
17 int main() 
18 { 
19     base obj(98); 
20     cout<<obj.get_i()<<endl 
21         <<obj.get_j()<<endl; 
22 
23     return 0; 
24 }