C++多重继承

 1 #include <iostream>
 2 
 3 using namespace std;
 4 
 5 class A {
 6 public:
 7     A(int a,int b);
 8     ~A();
 9 protected:
10     int m_a, m_b;
11 };
12 A::A(int a,int b):m_a(a),m_b(b) { cout << "A construction" << endl; }
13 A::~A() { cout << "A destruction" << endl; }
14 
15 class B {
16 public:
17     B(int c,int d);
18     ~B();
19 protected:
20     int m_c, m_d;
21 };
22 B::B(int c,int d) :m_c(c),m_d(d) { cout << "B construction" << endl; }
23 B::~B() { cout << "B destruction" << endl; }
24 
25 /*class C : public B {
26 public:
27     C();
28     ~C();
29 };
30 C::C() { cout << "C construction" << endl; }
31 C::~C() { cout << "C destruction" << endl; }*/
32 
33 class D : public A, public B {
34 public:
35     D(int, int, int, int,int );
36     ~D() { cout << "D destruction" << endl; };
37     void display();
38 
39 private:
40     int m_e;
41 };
42 
43 D::D(int a,int b,int c,int d,int e):A(a,b),B(c,d),m_e(e){ cout << "D construction" << endl; }
44 
45 void D::display() {
46     cout << m_a << m_b << m_c << m_d << m_e << endl;
47 }
48 
49 int main()
50 {
51     std::cout << "Hello World!\n";
52     D obj(1,2,3,4,5);
53     obj.display();
54     return 0;
55 }

 1 #include <iostream>
 2 
 3 using namespace std;
 4 
 5 class A {
 6 public:
 7     A(int a,int b);
 8     ~A();
 9         void show();
10 protected:
11     int m_a, m_b;
12 };
13 A::A(int a,int b):m_a(a),m_b(b) { cout << "A construction" << endl; }
14 A::~A() { cout << "A destruction" << endl; }
15 void A::show(){
16     cout<<m_a<<"   "<<m_b<<endl;
17 }
18 
19 class B {
20 public:
21     B(int c,int d);
22     ~B();
23         void show();
24 protected:
25     int m_c, m_d;
26 };
27 B::B(int c,int d) :m_c(c),m_d(d) { cout << "B construction" << endl; }
28 B::~B() { cout << "B destruction" << endl; }
29 void B::show(){
30         cout<<m_c<<"   "<<m_d<<endl;
31 }
32 
33 /*class C : public B {
34 public:
35     C();
36     ~C();
37 };
38 C::C() { cout << "C construction" << endl; }
39 C::~C() { cout << "C destruction" << endl; }*/
40 
41 class D : public A, public B {
42 public:
43     D(int, int, int, int,int );
44     ~D() { cout << "D destruction" << endl; };
45     void display();
46 
47 private:
48     int m_e;
49 };
50 
51 D::D(int a,int b,int c,int d,int e):A(a,b),B(c,d),m_e(e){ cout << "D construction" << endl; }
52 
53 void D::display() {
54     cout << m_a << m_b << m_c << m_d << m_e << endl;
55         A::show();    //调用A类的函数
56         B::show();    //调用B类的函数
57 }
58 
59 int main()
60 {
61     std::cout << "Hello World!\n";
62     D obj(1,2,3,4,5);
63     obj.display();
64     return 0;
65 }