이중 포인터 / 포인터 배열 객체 생성

 

#include <stdio.h>
 
#define EXAM_1 (1)
 
#if(EXAM_1)
class Item // 추상 클래스
{
public:
    virtual void Show() = 0; // 순수 가상함수
};
 
class _File : public Item
{
public:
    virtual void Show() { printf("_FILE\n"); }
};
 
class Folder : public Item
{
public:
    virtual void Show() { printf("Folder\n"); }
};
#else
class Item
{
public:
    void Show() { printf("Item\n"); }
};
 
class _File : public Item
{
public:
    void Show() { printf("_FILE\n"); }
};
 
class Folder : public Item
{
public:
    void Show() { printf("Folder\n"); }
};
#endif
 
int main()
{
#if(EXAM_1)
    Item **p = new Item * [3];
     
    for (int i = 0; i < 3; ++i)
    {
        if (i % 2 == 0)
            p[i] = new _File();
        else
            p[i] = new Folder();
 
        p[i]->Show();
    }
 
    for (int i = 0; i < 3; i++)
    {
        delete p[i];
        p[i] = NULL;
    }
 
    delete[]p;
#else
    Item *p[3];
 
    for (int i = 0; i < 3; ++i)
    {
        if (i % 2 == 0)
            p[i] = new _File();
        else
            p[i] = new Folder();
 
        p[i]->Show();
    }
 
    for (int i = 0; i < 3; i++)
    {
        delete p[i];
        p[i] = NULL;
    }
#endif
    return 0;
}