C++学习(19)

 1 //使派生类C只有公共基类A的一个成员变量a
 2 #include<iostream.h>
 3 
 4 class A{
 5     protected:
 6         int a;
 7     public:
 8         A(int aa){
 9             a=aa;
10         }
11         ~A(){}
12 };
13 
14 class B1:virtual public A{
15     protected:
16         int b1;
17     public:
18         B1(int aa,int bb1):A(aa){
19             b1=bb1;
20         }
21         ~B1(){}
22 };
23 
24 class B2:virtual public A{
25     protected:
26         int b2;
27     public:
28         B2(int aa,int bb2):A(aa){
29             b2=bb2;
30         }
31         ~B2(){}
32 };
33 
34 
35 class C:public B1,public B2{
36     protected:
37         int c;
38     public:
39     //    C(int aa1,int aa2,int aa3,int bb1,int bb2,int cc):A(aa1),B1(aa2,bb1),B2(aa3,bb2){
40     //        c=cc;
41     //    }
42 
43         C(int aa,int bb1,int bb2,int cc):A(aa),B1(aa,bb1),B2(aa,bb2){
44             c=cc;
45         }
46         ~C(){}
47         void printA()const{
48             cout<<"a="<<a<<endl;
49         }
50 };
51 int main(){
52     C myC(1,2,3,4);
53     myC.printA();
54     return 0;
55 }