NULL printing a value 0xbf940000 and not a zero

hello all,
in the following code a -> next should print zero, but it is giving the output as 0xbf940000

#include<iostream.h>
#include<conio.h>
#include<stdio.h>
class Node
{
   public:
   int data;
   Node *next;
   Node(int n=1)
   {
    data=10;
    next=0;
   }
};
void main()
{
 Node *a;
 clrscr();
 a=new Node();
 cout<<a->data<<endl;
 cout<<a->next<<endl;
 getch();
}

Try passing a number into the constructor, by not giving it a number you may be telling it not to use your own constructor but a do-nothing default constructor..

You should always write a default constructor, since it's used in a surprising number of situations.

i string with printf instead of cout and i got 0

I am not sure which platform or compiler you are using. The use of <iostream.h>, <conio.h>, void main(), etc. would suggest you are on a Windows platform.

The following gives the expected output on modern Linux platforms:

#include <iostream>

using namespace std;

class Node
{
   public:
   int data;
   Node *next;

   Node()
   {
       data=10;
       next=0;
   }
};

int main()
{
   Node *a;
   a = new Node();

   cout << a->data << endl;
   cout << a->next << endl;

   return 0;
}