Predict the output of following C++ programs.

Question 1

 1 #include<iostream>
2 using namespace std;
3
4 class Base
5 {
6 public:
7 int fun()
8 {
9 cout << "Base::fun() called";
10 }
11 int fun(int i)
12 {
13 cout << "Base::fun(int i) called";
14 }
15 };
16
17 class Derived: public Base
18 {
19 public:
20 int fun(char x)
21 {
22 cout << "Derived::fun(char ) called";
23 }
24 };
25
26 int main()
27 {
28 Derived d;
29 d.fun();
30 return 0;
31 }

  Output: Compiler Error.
  In the above program, fun() of base class is not accessible in the derived class. If a derived class creates a member method with name same as one of the methods in base class, then all the base class methods with this name become hidden in derived class.

Question 2

 1 #include<iostream>
2 using namespace std;
3 class Base
4 {
5 protected:
6 int x;
7 public:
8 Base (int i)
9 {
10 x = i;
11 }
12 };
13
14 class Derived : public Base
15 {
16 public:
17 Derived (int i):x(i)
18 {
19 }
20 void print()
21 {
22 cout << x ;
23 }
24 };
25
26 int main()
27 {
28 Derived d(10);
29 d.print();
30 }

  Output: Compiler Error
  In the above program, x is protected, so it is accessible in derived class. Derived class constructor tries to use initializer list to directly initialize x, which is not allowed even if x is accessible. The members of base class can only be initialized through a constructor call of base class.

  Following is the corrected program.

 1 #include<iostream>
2 using namespace std;
3 class Base
4 {
5 protected:
6 int x;
7 public:
8 Base (int i)
9 {
10 x = i;
11 }
12 };
13
14 class Derived : public Base
15 {
16 public:
17 Derived (int i):Base(i)
18 {
19 }
20 void print()
21 {
22 cout << x;
23 }
24 };
25
26 int main()
27 {
28 Derived d(10);
29 d.print();
30 }

  Output:

  10

  Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

  转载请注明:http://www.cnblogs.com/iloveyouforever/

  2013-11-27  16:34:25

Output of C++ Program | Set 16的更多相关文章

  1. Output of C++ Program | Set 18

    Predict the output of following C++ programs. Question 1 1 #include <iostream> 2 using namespa ...

  2. Output of C++ Program | Set 17

    Predict the output of following C++ programs. Question 1 1 #include <iostream> 2 using namespa ...

  3. Output of C++ Program | Set 15

    Predict the output of following C++ programs. Question 1 1 #include <iostream> 2 using namespa ...

  4. Output of C++ Program | Set 14

    Predict the output of following C++ program. Difficulty Level: Rookie Question 1 1 #include <iost ...

  5. Output of C++ Program | Set 13

    Predict the output of following C++ program. 1 #include<iostream> 2 using namespace std; 3 4 c ...

  6. Output of C++ Program | Set 11

    Predict the output of following C++ programs. Question 1 1 #include<iostream> 2 using namespac ...

  7. Output of C++ Program | Set 9

    Predict the output of following C++ programs. Question 1 1 template <class S, class T> class P ...

  8. Output of C++ Program | Set 7

    Predict the output of following C++ programs. Question 1 1 class Test1 2 { 3 int y; 4 }; 5 6 class T ...

  9. Output of C++ Program | Set 6

    Predict the output of below C++ programs. Question 1 1 #include<iostream> 2 3 using namespace ...

随机推荐

  1. Nessus home版插件更新

    1,进入服务器停止服务 service nessusd stop 2,进入目录执行命令获取Challenge code cd /opt/nessus/sbin/ ./nessuscli fetch - ...

  2. docker commit 制作自定义tomcat镜像

    官网下载的tomcat一般存在漏洞,在生产环境中一般是自己下载jdk和tomcat制作成一个新的镜像使用 1.将jdk和tomcat上传 2.生成 c3 容器 3.将jdk和tomcat拷贝到c3容器 ...

  3. Connected to an idle instance.

    Connected to an idle instance:连接到空闲实例 原因:数据库或者监听没启动

  4. 02-Java中的锁详解

    I. 使用Lock接口 只要不涉及到复杂用法,一般采用的是Java的synchronized机制 不过,Lock可以提供一些synchronized不支持的机制 非阻塞的获取锁:尝试获取锁,如果能获取 ...

  5. C++ 入门到进阶 学习路线

    前言 学习这件事不在乎有没有人教你,最重要的是在于你自己有没有觉悟和恒心. -- 法布尔 简介 随着互联网及互联网+深入蓬勃的发展,经过40余年的时间洗礼,C/C++俨然已成为一门贵族语言,出色的性能 ...

  6. 蓝图before request

    方法1 @bp.before_request def test(): print("test") 方法2 def bp_before_request(): print(test) ...

  7. PLSQL批量执行SQL文件方法

    当需要执行多个sql文件,或者某个脚本中,sql语句数量很多时,手动逐个逐条执行不是一个明智的选择. PLSQL为我们提供了便捷的工具.使用方式如下: [工具]--[导入表]--[SQL插入]--[选 ...

  8. sql关联修改

    UPDATE  p  set p.ClientID = c.id  from PaymentTable p left JOIN ClientTable c on p.ClientID = c.Clie ...

  9. Python基础(类和实例)

    class Point(object): def __init__(self,name,score): self.__name = name self.__score = score def prin ...

  10. Django笔记&教程 6-4 forms进阶操作,重写forms方法

    Django 自学笔记兼学习教程第6章第4节--forms进阶操作,重写forms方法 点击查看教程总目录 1 - 重写clean方法 在本章第三节中,我们举了个注册学生账号的例子,里面我们使用模型来 ...