/* A demo program to show dynamic variable
 */
#include <iostream>
using namespace std;

void Pause()
{
	cout <<"Press any key to continue:";
	char key;
	cin >> key;
}

int main()
{
 	int *p=NULL;
	int *q; 


	cout <<"--------------------------------------------------------------- \n";
	cout <<" Dynamically allocate a new int variable, save its address in p\n";
	cout <<"--------------------------------------------------------------- \n";
	p = new int;	//assign the address of variable a to p 
	cout <<"Pointer p=" << p << ", pointing to int with value" << *p << endl; 
	Pause();
	cout <<endl<<endl;

	cout <<"--------------------------------------------------------------- \n";
	cout <<"Accessing the int via pointer p: *p = 100 \n";
	cout <<"--------------------------------------------------------------- \n";
	*p = 100; 	// assign 100 to the int variable that p is pointing to 
	cout <<"After the assignment, the variable is" << *p << endl;
	Pause();
	cout <<endl<<endl;

	
	cout <<"--------------------------------------------------------------- \n";
	cout <<"Making q pointing to same place as p: q = p\n";
	cout <<"--------------------------------------------------------------- \n";
	q = p;	// copy p's value to q, now q also cotnains a's address
	cout <<"Pointer q=" << q << endl;
	cout <<"Accessing a through pointer q, *q stores value" << *q << endl;
	Pause();
	cout <<endl<<endl;

	cout <<"--------------------------------------------------------------- \n";
	cout <<"Free the int variable that p points to \n";
	cout <<"--------------------------------------------------------------- \n";
	delete p;

	cout <<"pointer p " << p << " is now pointing to a variable that is no more there\n";
	p = q = NULL;  //Important to do so! 

}