Linked Lists

[yayu]

Can someone explain how this works? I'm learning from a book but it either doesn't do a good job explaining or I can't grasp the concept.

//Link.h

class Link
{
public:
	string sName;
	Link* pNext;
};

Link* pHead = nullptr;

void add(Link* pLC)
{
	pLC->pNext = pHead;

	pHead = pLC;
}

Link* getData()
{
	string name;

	cout << "Enter Name: ";                           
	cin >> name;

	if(name == "Exit")
	{
		return 0;
	}

	Link* pLC = new Link;
	pLC->sName = name;
	pLC->pNext = 0;

	return pLC;
}

//main.cpp

#include <iostream>
#include <string>

using namespace std;

#include "Link.h"

int main()
{
	Link* pLC;

	while(pLC = getData())
	{
		add(pLC);
	}

	cout << "\nEntries: " << endl;

	for(Link *pOW = pHead; pOW; pOW = pOW->pNext)  
	{
		cout << pOW->sName << endl;
	}
	
	return 0;
}

Most of my confusion comes from the pNext. No idea how that is working. Help would be appreciated.

[keskiverto]

pNext is a pointer. In this case pNext is either 0, or knows where the next item of the list is. pNext is the directional link between items of the linked list.

[yayu]

Yes, but how does it know. I don't see how it is ever above 0. This line:

Link* pHead = nullptr

sets it 0 every time it goes into add(). Am I misreading it?

[keskiverto]

Only the first time. Same add changes pHead.

Bad style IMO. pHead is a global variable and holds the one and only list of the program.

[yayu]

Thank you.