/* This program demonstrates dynamic memory allocation.
 * Dynamic Memory allocation is when we
 * a. Allocate Memory outside the function call stack in heap memory
 * b. We do this during runtime (after the program has started running)
 *
 * The allocated memory must be explicitly destroyed by the programmer
 *
 * To allocate: Use the "new" operator/ keyword
 *
 * To deallocate: Use the "delete" operator/keyword
 */

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

int main()
{
    /* Dynamic memory
   * We declare a variable in dynamic (heap) space and then can ONLY access it
   * through a pointer
   * A variable in dynamic space is declared using the keyword "new"
   * Once we're done using the variable, it is cleared from memory using the "delete" keyword
   */

    int *ptr;
    ptr = new int;

    cout<<"Enter a number: ";
    cin>> * ptr;

    cout<<"Value of dynamic integer variable created: "<< * ptr <<endl;
    cout<<"Address of the pointer : "<< &ptr <<endl;
    cout<<"Address of dynamic integer variable created (and stored in ptr): "<< ptr <<endl;

    /* Once we're done with the variable, we need to deallocate the memory. 
     * That's the process of telling the OS "this memory is no longer in use"
     * To do that, use the delete operator.
     */

    delete ptr;

    return 0;
}