Object Pascal
lastmod 2025-12-10created 2025-12-104 edits
Object Pascal is a programming language developed by adding object-oriented concepts to Pascal. It is also widely known as the Delphi language.
It originated with the Object Pascal compiler developed for the Apple Lisa, the predecessor of the Apple Macintosh. The most widely known variant of Object Pascal is the "Delphi programming language" used in Borland/CodeGear's Delphi. Among products outside Borland/CodeGear, Free Pascal, which is developed as free software and closely resembles Delphi, also has nearly identical syntax.
Hello World
Apple's Object Pascal
program ObjectPascalExample;
type
THelloWorld = object
procedure Put;
end;
var
HelloWorld: THelloWorld;
procedure THelloWorld.Put;
begin
WriteLn('Hello, World!');
ReadLn;
end;
begin
New(HelloWorld);
HelloWorld.Put;
Dispose(HelloWorld);
end.
Turbo Pascal
program ObjectPascalExample;
type
PHelloWorld = ^THelloWorld;
THelloWorld = object
procedure Put;
end;
var
HelloWorld: PHelloWorld; { this is a pointer to a THelloWorld }
procedure THelloWorld.Put;
begin
WriteLn('Hello, World!');
end;
begin
New(HelloWorld);
HelloWorld^.Put;
Dispose(HelloWorld);
end.
Delphi Pascal
program ObjectPascalExample;
{$MODE DELPHI} { Only for free pascal or compile option -Mdelphi }
type
THelloWorld = class
procedure Put;
end;
procedure THelloWorld.Put;
begin
Writeln('Hello, World!');
end;
var
HelloWorld: THelloWorld; { this is an implicit pointer }
begin
HelloWorld := THelloWorld.Create; { constructor returns a pointer }
HelloWorld.Put;
HelloWorld.Free; { this line dereferences the pointer }
end.