C++类继承中的虚方法

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 
 4 class A {
 5     public:
 6         void Show() {
 7             cout << "A" << endl;
 8         }
 9 } ;
10 
11 class B : public A {
12     public:
13         virtual void Show() {
14             cout << "B" << endl;
15         }
16 } ;
17 
18 class C : public B {
19     public:
20         void Show() {
21             cout << "C" << endl;
22         }
23 } ;
24 
25 int main() {
26     A a; B b; C c;
27     A &s1 = b; A &s2 = c;
28     B &t1 = b; B &t2 = c;
29     s1.Show(); s2.Show();
30     t1.Show(); t2.Show();
31     return 0;
32 }

View Code

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 
 4 class A {
 5     public:
 6         virtual void Show() { // 将virtual去掉运行做对比
 7             cout << "A" << endl;
 8         }
 9 } ;
10 
11 class B : public A {
12     public:
13         virtual void Show() {
14             cout << "B" << endl;
15         }
16 } ;
17 
18 class C : public A {
19     public:
20         void Show() {
21             cout << "C" << endl;
22         }
23 } ;
24 
25 class D : public A {
26 } ;
27 
28 int main() {
29     ios::sync_with_stdio(0);
30     A a; B b; C c; D d;
31     A &t1 = a; A &t2 = b; A &t3 = c; A &t4 = d;
32     t1.Show(); t2.Show(); t3.Show(); t4.Show();
33     a.Show(); b.Show(); c.Show(); d.Show();
34     return 0;
35 }

View Code

——written by Lyon

posted @ 2014-07-14 20:38 LyonLys 阅读(262) 评论(0) 收藏举报

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