program exPointertoPointers;

type

   iptr = ^integer;

   pointerptr = ^ iptr;

​

var

   num: integer;

   ptr: iptr;

   pptr: pointerptr;

   x, y : ^word;

​

begin

   num := 3000;

​

   (* take the address of var *)

   ptr := @num;

​

   (* take the address of ptr using address of operator @ *)

   pptr := @ptr;

​

   (* let us see the value and the adresses *)

   x:= addr(ptr);

   y := addr(pptr);

​

   writeln('Value of num = ', num );

   writeln('Value available at ptr^ = ', ptr^ );

   writeln('Value available at pptr^^ = ', pptr^^);

   writeln('Address at ptr = ', x^);

   writeln('Address at pptr = ', y^);

end.