program classExample;

​

{$MODE OBJFPC} //directive to be used for creating classes

{$M+} //directive that allows class constructors and destructors

type

   Books = Class 

   private 

      title : String; 

      price: real;

   public

      constructor Create(t : String; p: real); //default constructor

      procedure setTitle(t : String); //sets title for a book

      function getTitle() : String; //retrieves title

      procedure setPrice(p : real); //sets price for a book

      function getPrice() : real; //retrieves price

      procedure Display(); // display details of a book

end;

var

   physics, chemistry, maths: Books;

​

//default constructor 

constructor Books.Create(t : String; p: real);

begin

   title := t;

   price := p;

end;

​

procedure Books.setTitle(t : String); //sets title for a book

begin

   title := t;

end;

​

function Books.getTitle() : String; //retrieves title

begin

   getTitle := title;

end;

​

procedure Books.setPrice(p : real); //sets price for a book

begin

   price := p;

end;

​

function Books.getPrice() : real; //retrieves price

begin

   getPrice:= price;

end;

​

procedure Books.Display();

begin

   writeln('Title: ', title);

   writeln('Price: ', price:5:2);

end;

​

begin 

   physics := Books.Create('Physics for High School', 10);

   chemistry := Books.Create('Advanced Chemistry', 15);

   maths := Books.Create('Algebra', 7);

   physics.Display;

   chemistry.Display;

   maths.Display;

end.