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From: jeffb@yang.earlham.edu (Jeff Braun)
Newsgroups: comp.lang.pascal
Subject: HELP WITH TURBO PASCAL 5.5 OOP!!! Please!
Message-ID: <2994@yang.earlham.edu>
Date: 14 Oct 90 22:32:12 GMT
Organization: Earlham College, Richmond, Indiana
Lines: 40

Hello,  I'm very new to Turbo Pascal 5.5 and as well to Object-Oriented 
programming in general and I have a few questions if anyone could help me:

1.  What is the purpose of using the reserved word CONSTRUCTOR?  I 
    understand that every "...object that has virtual methods must have a 
    constructor" (Turbo Pascal: Object-Oriented Programming Guide, 
    page 26) but I don't seem to understand what it is telling the compiler?
    I sort-of understand that it's used for intialization of a object with
    virtual methods (right?), but what does it initialize and can they be 
    used for anything other than intialization?  So if I have an this piece of 
    code taken from page 42 of TP:OOPG:

       Location = object
          X,Y : integer;
          procedure Init(Initx, Inity :intger);
          function Getx: integer;
          function Gety: integer; 
       end;

       PointPtr = ^Point;

       Point = object(Location)
         Visible : boolean;
         constructor Init(Initx, Inity : integer);
         procedure Show virtual;
         procedure Hide virtual;
       end;                                    
  
    
    Is it used in constructing the X and Y variables in Point or is it 
    allowing for PointPtr to be Initialized at run time as an object pointer?

2.  What about DESTRUCTORS? Are they like DISPOSE in Turbo Pascal?  

I realize these are very simple questions, but I'm just a little 
(maybe a little more than a little) confused.   

Thanks.

Jeffb@yang.earlham.edu