Deleting a linked list

[Stormboy]

Hi,
If I have a linked list, how can I delete it at the end of my program to free the memory taken up. I know I have to use delete but not sure how to use it in this case. Help me out on this please.

Here is the code that I have:

#include <iostream>
#include <cstdlib>

using namespace std;

struct Numlist
{
    int num; //Number
    Numlist * next; //Pointer to the next node
};

int main()
{
    srand(time(0));

    Numlist * mainList;
    Numlist * navigator;

    mainList = new Numlist;
    navigator = mainList;

    //Keep on making a new list and add values until number of lists is 5.
    for(int i = 0; i < 5; i++)
    {
        if(i <= 3)
        {
            navigator->num = rand() % 100;
            navigator->next = new Numlist;
            navigator = navigator->next;
        }
        else if(i == 4)
        {
            navigator->num = rand() % 100;
            navigator->next = NULL;
        }
    }

    //Set the navigator back to the beginning of the list
    navigator = mainList;

    //Print out the values from the list
    for(int j = 0; j < 5; j++)
    {
        cout << "Number in list " << j+1 << ": " << navigator->num << endl;
        navigator = navigator->next;
    }

    return 0;
}

[keskiverto]

Line 42: while ( NULL != navigator )
Operate based on what really is in the list rather than by hardcoded parameters.


Deletion:
1. Numlist could have a destructor that deletes next. Then delete mainList.
or
2. Loop through the list like when printing.

{
  auto victim = navigator;
  navigator = navigator->next;
  delete victim;
}

[Stormboy]

Hey keskiverto! Thanks for your reply. Could you demonstrate solution method #1? Thanks :).

[keskiverto]

Start by looking at some examples of destruction:
http://en.wikipedia.org/wiki/Destructor_%28computer_programming%29#In_C.2B.2B
http://www.cprogramming.com/tutorial/constructor_destructor_ordering.html
http://www.tutorialspoint.com/cplusplus/cpp_constructor_destructor.htm

[Stormboy]

Allright, thanks for your help! :)