====== Introduction ======

<code C>
/* Reference */
#include <stdio.h>

int main()
{
  int a = 5;

  printf("The value of a is: %d\n", a);
  printf("The address of a is: %p\n", &a);

  return 0;
}
</code>

<code C>
/* Pointer */
#include <stdio.h>

int main()
{
  int a;
  int *p;

  a = 5;
  p = &a;

  printf("The value of a is: %d\n", a);
  printf("The address of a is: %p\n", &a);
  printf("The address of a is: %p\n", p);

  return 0;
}
</code>

<code C>
/* Dereference */
#include <stdio.h>

int main()
{
  int a;
  int *p;

  a = 5;
  p = &a;

  printf("The value of a is: %d\n", a);
  printf("The value of a is: %d\n", *p);
  printf("The address of a is: %p\n", &a);
  printf("The address of a is: %p\n", p);

  *p = 10;

  printf("New value of a is: %d\n", a);
  printf("New value of a is: %d\n", *p);
  printf("The address of a is: %p\n", &a);
  printf("The address of a is: %p\n", p);


  return 0;
}
</code>

<code C>
/* Uninitialize */
#include <stdio.h>

int main()
{
  int *p;
  int n = *p;

  printf("Uninitialized value of n is: %d\n", n);
  printf("Uninitialized value of p is: %p\n", p);

  return 0;
}
</code>