Static Var 静态成员

#include <iostream>
#include <stdlib.h>
#include <memory.h>
using namespace std;

class CDemo
{
public:
    CDemo(const char* str);
    ~CDemo();
    void showObjectName();   

private:
    char name[20];
    static int static_var;
};

int CDemo::static_var = 1000;

CDemo::CDemo(const char* str)
{
    strncpy(name,str,20);
    cout << "Constructor called for " << name << "\n";
    cout << "Constructor called for " << CDemo::static_var << "\n";
}

CDemo::~CDemo()
{
    cout << "Destructor called for " << name << "\n";
};

void CDemo::showObjectName()   //显示对象名
{
    cout << "showObjectName() name: " << name << endl;
    cout << "showObjectName() static_var: " << static_var << endl;
}


void func()
{
    cout << "enter func" << endl; 
    CDemo LocalObjectInFunc("LocalObjectInFunc"); 
    static CDemo staticObject("StaticObject");    
    staticObject.showObjectName();
    CDemo* pHeapObjectInFunc = new CDemo("HeapObjectInFunc"); 
    cout << "exit func" << endl; 
} 


CDemo GlobalObject("GlobalObject"); 

int main()
{
    cout << "enter main" << endl;
    static CDemo staticObjectInMain("staticObjectInMain");
    CDemo localObjectInMain("LocalObjectInMain");  
    CDemo* pHeapObjectInMain = new CDemo("HeapObjectInMain"); 

    cout << "In main, before calling func\n\n\n"; 
    func();
    cout << "\n\n";                             

    func();                 //staticObject静态对象已经存在，不再创建!                                    
    cout << "\n\nIn main, after calling func\n";  //14

    
    //staticObject.showObjectName();  //error C2065: “staticObject”: 未声明的标识符
    staticObjectInMain.showObjectName();
    GlobalObject.showObjectName();
    cout << "In main, after GlobalObject.showObjectName(): ";
    return 0;
}