class student
{
public:  
  student(char *pName = "No name")  
  {
 strcpy((char*)name, pName);
 semesterhours = 0;
  } 
protected:
  void addcourse(int hours)  
  {
 semesterhours += hours;
 cout << "semesterhours" << semesterhours << endl;
  }
public:
 int pubval;
protected:  
 int proval;
//private:
  char  name[40];  
  int  semesterhours;  
private:
 int prival;
};

class graduatestudent:protected   student  
{
public:
 void addcoursetoo(int h)
 {
  pubval = 10;
  proval = 20;
  //prival = 30;
  prival2 = 40;
  student::addcourse(h);
 }
private:
 int prival2;
}; 

class citizen:private graduatestudent
{
public:
 void addcourse3(int h)
 {
  addcoursetoo(100);
  addcourse(400);
  pubval = 200;
  proval = 300;
 }
};

int _tmain(int argc, _TCHAR* argv[])
{
 student   ds("undergradute");  
   graduatestudent   gs;  
 //gs.addcourse(30);  
 gs.addcoursetoo(40);

 getchar();

 return 0;
}

 3. 定义只能创建一个实例的类
#include "stdafx.h"
#include <windows.h>
#include <iostream>

#include <iostream>
using namespace std;

class   CDebug  
  {  
  public:  
   ~CDebug(){} 
   
          void   Print(const char *str)
    {
     printf(str);
    }
          static   CDebug &GetInstance()    
          {  
    static CDebug debug;
                 //return   s_debug;    
    return debug;
    
          }
    void SetName(char * n)
    {
     strcpy(Name, n);
    }
    void PrintName(void)
    {
     printf("Name: %s\n", Name);
    }
  private:  
          HANDLE   m_StdOut; 
    char Name[10];

              static    CDebug  * s_debug;    
          //防止直接生成实例  
    CDebug(){}  
  };  

int _tmain(int argc, _TCHAR* argv[])
{
 //CDebug object = CDebug::GetInstance();
 CDebug::GetInstance().Print("hello dshe\n");
 CDebug::GetInstance().SetName("ASON");
 CDebug::GetInstance().PrintName();

 CDebug object2 = CDebug::GetInstance();
 object2.PrintName();
 getchar();

 return 0;
}

 4.
#include "stdafx.h"
#include "iostream"
using namespace std;

class MyClass
{
public:
 MyClass(char * n = "No Name")
 {
  printf("MyClass\n");
  strcpy(m_Name, n);
 }
 static MyClass GetObj(char * nn)
 {
  return MyClass(nn);
 }
 ~MyClass()
 {
  printf("~MyClass\n");
 }
 void Print(void)
 {
  printf("Name: %s\n", m_Name);
 }
private:
 char m_Name[10];
};

int _tmain(int argc, _TCHAR* argv[])
{
 MyClass p;
 p = MyClass("aAAbBB");
 p.Print();
 getchar();

 return 0;

<window id="HideShowTesting" title="Hide/Show Testing" width="300" height="200"
        xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
<script>
function checkPositions()
{
  // Get references to the hidden and collapsed labels
  var hidden=document.getElementById("hiddenLabel");
  var collapsed=document.getElementById("collapsedLabel");

  // Get the size of the hidden label using the width and height properties
  // of the boxObject. Use alert() to dispaly the size.
  var val="Size of hidden element: "+ hidden.boxObject.width+","+hidden.boxObject.height;
  alert(val);

  // Remove the hidden attribute so that the label appears.
  hidden.removeAttribute("hidden");

  // Get the size of the collapsed label.
  val="Size of collapsed element: "+ collapsed.boxObject.width+","+collapsed.boxObject.height; 
  alert(val);

  // Remove the collapsed attribute so that the label appears.
  collapsed.removeAttribute("collapsed");
  // or collapsed.collapsed = false;

  val="Size of collapsed element: "+ collapsed.boxObject.width+","+collapsed.boxObject.height;
  alert("again: " + val);
}
</script>

<button label="Check Positions" oncommand="checkPositions();"/>
<hbox>
<label id="hiddenLabel" hidden="true" value="aaa" style="background-color: #FFFF00;"/>
<label id="collapsedLabel" collapsed="true" value="bbbccc" style="background-color: #00FFFF;"/>
</hbox>
</window>