kann mir das vielleicht mal jemand erklären anhand meines beispiels ?

vielen dank schonmal

#include <iostream>
#include <string>
using namespace std;

class Name
	{
		public:
			Name() {}
			Name(char *vn,char *nn){strcpy(vorname,vn); strcpy(nname,nn); }
			~Name() {}
			void print() {cout << vorname << endl <<nname << endl;}

		private:
		char vorname[20];
		char nname[20];

	};

class Namelistelement :public Name
	{

		public:
			Namelistelement() {}
			~Namelistelement() {}

		Namelistelement *next;
		Namelistelement *previous;
		Name value;

	};

class Namelist :public Namelistelement
	{	

		public:
			Namelist() {first==NULL; end==NULL;}
			~Namelist() {}

			// push
			int push(Name &obj) {

			Namelistelement *zeiger=new Namelistelement;
			zeiger->value=obj;
			zeiger->next=first;
			zeiger->previous=first;

			first=zeiger;
			end=zeiger;
			return 0;

							}
			//pop
			Name pop(void)     {

			 Name dummy;
		     Namelistelement *zeiger=first;
			 dummy=zeiger->value;
			 first=zeiger->next;

			 delete zeiger;

				dummy.print();
		return *this;
		}

		private:
			Namelistelement *first;
			Namelistelement *end;
	};

int main()

{

Name objekt1("Nadine","Muster");
Name objekt2("Max","Mustermann");
Name objekt3("Jim","Morris");

Namelist liste;

liste.push(objekt1);
liste.push(objekt2);
liste.push(objekt3);

liste.pop();
liste.pop();
liste.pop();

}

#include <iostream>
#include <string>
using namespace std;

class Name
	{
		public:
			Name() {}
			Name(char *vn,char *nn){strcpy(vorname,vn); strcpy(nname,nn); }
			~Name() {}
			void print() {cout << vorname << endl <<nname << endl;}

		private:
		char vorname[20];
		char nname[20];

	};

class Namelistelement :public Name
	{

		public:
			Namelistelement() {}
			~Namelistelement() {}

		Namelistelement *next;
		Namelistelement *previous;
		Name value;

	};

class Namelist :public Namelistelement
	{	

		public:
			Namelist() {first=NULL; end=NULL;}
			~Namelist() 
			{
				while( !empty() )
				pop();
			}

			// push
			int push(Name &obj) {

			Namelistelement *zeiger=new Namelistelement;
			zeiger->value=obj;
			zeiger->next=0;
			zeiger->previous=end;

			if (empty())
				first=zeiger;
			else
				end->next=zeiger;

			end=zeiger;
			return 0;}

			//pop
			Name pop(void)     {
				Name dummy;

		     Namelistelement *zeiger=end;
			 zeiger->value=dummy;
			 end=end->previous;
			 if (end=NULL)
				 first=NULL;
			 else
				 end->next=NULL;

			 delete zeiger;

		 dummy.print();
	     return *this;
		}

		private:
			Namelistelement *first;
			Namelistelement *end;
			bool empty() {return first==0; }
			Namelist & operator = ( Namelist & );
};
int main()

{

Name objekt1("Nadine","Muster");
Name objekt2("Max","Mustermann");
Name objekt3("Jim","Morris");

Namelist liste;

liste.push(objekt1);
liste.push(objekt2);
liste.push(objekt3);

liste.pop();
liste.pop();
liste.pop();

}